General Study Guide - Ontario Police College

What to Study (Information from Ontario Police College) 

“The Core Competencies and Ministry Accredited Training Standards are the basis for 

the Re-Certification Examination.” 

They are available online at http://www.opconline.ca/ident/2009/index.html. 

The following will also assist in preparation for the exams: 

1. Quantitative-Qualitative Friction Ridge Analysis an Introduction to Basic 

and Advanced Ridgeology, Ashbaugh, David R. , 1999. 

2. Handbook of Forensic Evidence for the Investigator, Centre of Forensic 

Sciences (October 2, 2007). 

Core Competencies and Technical Competencies 

The core competencies of forensic identification officers (from O. Reg. 3/99 Adequacy 

Regulation) were revised in 2006. Technical Competencies that are developed in 

training have been identified by the Ontario Police College and the Canadian Police 

College. 

“Together, the core competencies and the technical competencies provide the 

foundation for all questions on the re-certification examination.”

Core Competencies 

The forensic identification specialist must be able to: 

1. ATTEND CRIME SCENES 

a) Determine priority of call 

b) Determine resources required and available 

c) Schedule attendance of forensic identification specialist 

d) Arrive at scene promptly and adequately equipped to examine, collect, preserve and / or 

process physical evidence 

e) Become familiar with all available facts in the case to determine the sequence of events, 

victim impact, additional resources required and feasibility of recovering physical evidence 

f) Determine strategy and develop a plan of action to ensure safe and efficient forensic 

examination with minimal contamination of evidence 

g) Assess validity of information previously obtained 

h) Facilitate cooperation with investigators and other team members and assist primary 

investigator in conduct of forensic aspects of case 

i) Understand and comply with role and responsibilities as required by Ontario Major Case 

Management principles as per Ontario Regulation 354/04. 

2. RECORD CRIME SCENES 

a) Document the crime scene prior to forensic examination and / or disturbance, e.g., by 

photographs, videographs, tape recordings, written notes as appropriate 

b) Document individual items of evidence and their location, for investigational or court 

purposes 

c) Measure the overall scene and the relative location of recovered evidence to enable the 

preparation of accurate and detailed scale drawings for investigators and possible court 

presentation 

d) Document damage to private property incurred during the investigation 

3. EVIDENCE AT CRIME SCENES 

a) Minimize disturbance and contamination of the crime scene 

b) Locate, document, collect and preserve: 

friction ridge impression evidence 

two and three dimensional impression

evidence 

evidence for further examination at the 

forensic identification unit 

evidence for scientific analysis at a 

forensic laboratory 

other evidence as required for the 

investigation 

4. DOCUMENT AND PRESERVE CONTINUITY 

As per local service requirements: 

a) Document initial forensic examination and prepare report to assist in investigation 

b) Update the primary investigator on the status of the forensic evidence as laboratory 

examinations / processes are completed 

c) Maintain continuity of evidence and preserve it for further examination and / or 

presentation to court 

d) Arrange the timely and safe return of personal property 

5. PROCESS AND ANALYZE EVIDENCE 

a) Assess the evidence for completeness to enable the reconstruction of the events of the 

crime 

b) Submit / share evidence with the appropriate agencies as required, e.g., Forensic 

laboratory, central fingerprint repository and other police services. 

c) Preserve and safeguard original photographic negatives and provide photographic prints 

as required for investigational and court purposes 

d) Preserve and safeguard original videotapes and provide a visual record of evidence for 

investigational and court purposes 

e) Analyze, compare, evaluate, individualize and preserve friction ridge impressions 

f) Confirm criminal record through comparison and matching fingerprint impressions 

g) Analyze, compare, evaluate, individualize and preserve two- and three-dimensional 

impressions 

h) Identify and / or verify the origin of other physical evidence e.g. physical match; trace 

evidence 

i) Select, process and preserve evidence for court and investigational purposes

6. MANAGE EQUIPMENT AND SUPPLIES 

a) Make equipment and supplies available and operational on a continual basis 

b) Maintain the work area in a clean, safe, and orderly fashion in compliance with Health and 

Safety requirements 

7. PREPARE FOR COURT, FORMAL INQUIRY AND CORONER'S INQUESTS AND CLOSE FILES 

a) Prepare evidence for investigational and / or court purposes in a suitable, easily 

understandable format 

b) Inform all relevant parties of the evidence to be submitted in court 

c) Assist counsel in preparing for court 

d) Present and explain forensic evidence in a professional and understandable manner using 

appropriate scientific language 

e) Conclude forensic examination file in accordance with police service and court policies 

8. ONGOING TRAINING AND SELF DEVELOPMENT 

a) Engage in regular, ongoing training and / or professional development activities to ensure 

currency in knowledge, skills and abilities in the field 

b) Keep abreast of new forensic methods and technology 

c) Join professional organizations and / or read professional journals and publications 

d) Comply with requirements of the professional development model as prescribed 

Technical Competencies 

Photography and the photographic process: 

a. Photographic techniques for crime scenes and small objects 

b. Exposure and contrast control 

c. Use of filters, lenses of differing focal lengths and other accessories 

d. Close-up photography 

e. Electronic flash techniques (e.g. oblique, tented, bounce flash) 

f. Control of light and lighting techniques (e.g. long exposures through available light, oblique 

lighting, polarizing filter etc.) 

g. Lighting for large scenes at night (e.g. paint by light, multiple flash in the scene, multiple 

flash at the camera; rear curtain synchronization etc.)

h. Use alternate lighting sources and techniques including ultraviolet and infrared and other 

specific bandwidths of visible light in forensic applications 

i. Special camera and lighting techniques for two and three dimensional impressions, such 

as, fingerprints, tires and footwear 

j. Processing and management of images including scanning and storage of images 

Online References: http://www.crime-scene-investigator.net/csi-photo.html 

http://www.eneate.freeserve.co.uk/digital.PDF ; http://www.eneate.freeserve.co.uk/evidence.PDF ; 

http://www.seanet.com/~rod/digiphot.html (Digital Photography as Legal Evidence); 

http://www.crime-scene-investigator.net/admissibilityofdigital.html (The Admissibility of Digital 

Photographs in Court); 

http://www.rcmp-learning.org/docs/ecdd1004.htm (Crime Scene Photography - RCMP); 

http://www.theiai.org/guidelines/swgit/index.php (SWGIT Documents) 

Criminalistics: 

a. History of fingerprinting 

b. Skin structure 

c. Philosophy, ethics and scientific principles and methodology of the identification process 

d. Ridgeology 

e. Identification of Criminals Act 

f. Recording fingerprints and palmprints 

Online Reference - http://www.crime-scene-investigator.net/prints.html 

g. Fingerprint and palmprint pattern recognition and digit determination 

Online References- Transfer Drive Folder: Re-Certification Study Material\Palm Prints; Re- 

Certification Study Material\Patterns Digit Determination 

h. Developing latent fingerprints (powder and chemical methods) 

i. Recovery and preservation of physical evidence 

Online References - http://www.crime-scene-investigator.net/collect.html ; 

http://www.ncjrs.gov/pdffiles1/nij/178280.pdf ; 

http://www.crime-scene-investigator.net/evidenc2.html ; 

http://www.crime-scene-investigator.net/footwear.html ; 

http://www.crime-scene-investigator.net/2dfootwear.html

j. Use of alternate light sources to search for evidence 

k. Preparation and submission of evidence for laboratory examination 

(Refer to Handbook of Forensic Evidence for the Investigator, Centre of Forensic Sciences (October 2, 

2007)) 

l. Search and comparison of physical evidence (including two and three dimensional 

impression such as fingerprints and footwear and evidence suitable for physical matching) 

O.P.C Forensic Identification Training Notes, Spring 2008 – “Search and Comparison of Fingerprint 

Impressions” Revised April 2001 

m. Crime scene measurement and sketching 

Online Reference - http://www.moval.edu/faculty/simmermanj/homicide/crime_scene_sketch.htm 

n. Preparation of charts 

o. Courtroom presentation of identification evidence 

Online Reference - 

p. Case law and statutes, regulatory and legislative environment for forensic identification 

Online Reference - http://www.justice.gc.ca/eng/dept-min/pub/pmj-pej/p9.html 

q. Fingerprinting deceased persons and awareness of other methods of identifying human 

remains 

O.P.C Forensic Identification Training Notes, Spring 2008 – 1) “Identifying the Dead”, O.P.C. 

Powerpoint Presentation; 2) “Verifying the Identity of Deceased Persons” 

r. Comply with quality assurance procedures 

s. Case documentation 

Online Reference -http://www.crime-scene-investigator.net/document.html 

t. Major case management Model, and responsibilities of the forensic specialist including 

responsibilities regarding search warrants 

O.P.C Forensic Identification Training Notes, Spring 2008 – Ontario Major Case Management Manual, 

Ministry of Community Safety and Correctional Services, October 1, 2004. 

Online Reference - http://www.crime-scene-investigator.net/searchingandexamining.html

History of Fingerprint Identification 

Early Pioneers: 

Alphonse Bertillon – (April 22 or 23, 1853-Feb. 13, 1914) 

Alphonse Bertillon, working in the dungeon like halls of the identification bureau of the Paris 

Prefecture of Police, devised a meticulous method of measuring body parts as a means of 

identification, known as ‘The Bertillon Method of Identification’, ‘Bertillonage’ or ‘Anthropometry’. 

It was first used in 1883 and was found to be slightly flawed in 1903 (known as the Will West Case). 

The West case didn’t end the use of Anthropometry but it did establish that Anthropometry didn’t 

individualize all people. Even though the Bertillon system didn’t provide perfect results, it did 

provide sufficient results and was very useful in its day. It was accepted as the world’s first scientific 

method of criminal identification. 

Bertillon is also credited with solving the first crime involving latent prints without having a suspect. 

Bertillon identified latent prints found on a piece of glass, from the murder scene of Joseph Reibel, 

as being left by Henri Leon Scheffer's. Bertillon found the identification by searching his files one 

person at a time. The date of the murder was October 17, 1902 and the identification was made on 

October 24, 1902. This is published in "Alphonse Bertillon: Father of Scientific Detection", Henry 

Rhodes (1956). 

William Herschel – came from an eminent scientific family. Both his father and grandfather were 

astronomers. He started researching fingerprints as early as 1858. His research only focused, 

however, on fingerprint permanency over a lifetime. Herschel used fingerprints as ‘signatures’ on 

contracts and jail sentencing documents and any opportunity to prevent fraud in India. 

Dr.Henry Faulds – In 1878 he discovered fingerprints on ancient pottery in Japan and began his 

extensive fingerprint research in both permanency and uniqueness. In Oct.1880 he was the 1st 

individual to publicly suggest using fingerprints for solving crime. In 1886 he tried to convince 

Scotland Yard to adopt the fingerprint system. 

Sir Francis Galton – A famous scientist, Galton’s most interesting contribution to the science of 

friction ridge identification was his method of distinguishing fingerprints having the same general 

pattern. He noticed that ridges did not proceed in unbroken lines across the finger but rather 

stopped abruptly, split, formed enclosures or connected with other ridges. These types of ridge 

characteristics are referred to as ‘Galton points’ still today. He used this comparison of ridge detail 

to confirm Herschel’s observations of fingerprint permanence. He published his book Finger Prints 

in 1892 and provided the systematic proof for the scientific basis of fingerprint identification which 

contributed to its general acceptance. 

Sir Edward Henry – In 1883, working as Chief of Police in India, he added thumbprints to 

anthropometric cards. He was given credit for coming up with a comprehensive system for 

fingerprint classification that is still used today.

Juan Vucetich – Employed as a statistician with the Central Police Department in LaPlata, Argentina 

and put in charge of setting up a bureau of Anthropometric Identification. Intriqued by an article 

about a lecture by Galton, “Patterns in Thumbs and Finger Marks”, he started experimenting with 

fingerprint collection. By September 1891 he had independently worked out a fingerprint 

classification system. Central Police was responsible for solving a case known as the first murder 

solved by fingerprints. In 1894, Vucetich published a book entitled, General Introduction to the 

Procedures of Anthropometry and Fingerprinting. In 1896 Argentina became the first country in the 

world to abolish anthropometry and file criminal records solely by fingerprint classification. 

(Ashbaugh, 1999) 

Edward Foster (1863-1956)- A Canadian police constable of the Dominion Police responsible for 

introducing the use of fingerprints for the purpose of identification to Canada. On July 21, 1908 an 

Order-in-Council was passed by the Canadian government sanctioning the use of fingerprints and 

that the provisions of “The Identification of Criminals Act” were applicable. A National Bureau was 

opened in February 1911 with a staff consisting of Foster, three assistants and a stenographer. The 

original files consisted of 2042 sets of fingerprints collected by Foster himself. The first conviction in 

Canada based on fingerprint evidence took place in 1914. Edward Foster gave expert evidence at 

the trial. In 1920 the Dominion Police was absorbed by the RCMP where Insp. Foster was in charge 

of the fingerprint bureau until his retirement in 1932. 

Scientific Researchers: 

Marcello Malphighi (1628 – 1694) 

An professor of anatomy from Italy who, in 1685, published a paper on friction skin based on his 

observations using the newly invented microscope. One of the layers of skin was named in his 

honour. His paper dealt primarily with the function of friction skin such as creating traction for 

walking and grasping. 

J.C.A. Mayer (1788) 

During the 1700's, Mayer was the first to recognize that although specific friction ridge 

arrangements may be similar, they are never duplicated. 

Arthur Kollmann (1883) 

In the late 1800's, Kollmann of Hamburg Germany, was the first researcher to address the formation 

of friction ridges on the fetus and the random physical stresses and tensions which may have played 

a part in their growth. 

Inez Whipple (1904) 

Ms. Whipple was a graduate from Brown University Rhode Island and also graduated from Smith 

College with a Masters of Art degree. She taught highschool biology for 4 years before taking on a 

teaching position with the Zoology Department at Smith College. In 1904, Inez Whipple published a 

paper that is considered by some as a landmark in the field of genetics and ridgeology. "The Ventral 

Surface of the Mammalian Chiridium - With Special Reference to the Conditions Found in Man" 

suggests that the development of the surfaces of the hands and feet (chiridia) of all mammals are 

similar to some degree. Her paper has certainly given us an insight into the possible evolutionary 

process of volar skin development on mammals.

Harris Hawthorne Wilder, Ph.D. (1918) 

After graduating from Amherst College in Massachusetts, Harris Hawthorne Wilder taught biology 

for three years at a Chicago high school. In 1889 he decided to concentrate his studies on anatomy 

at the University of Freiburg in Germany. He received a Ph.D. after two years and then returned to 

North America. In 1892 he accepted the position of Professor of Zoology at Smith College 

Massachusetts. His research included studies on morphology, methodology of plantar and palmar 

dermatoglyphics, genetics and racial differences. 

In 1918 Wilder and Bert Wentworth, a former Police Commissioner of Dover New Hampshire, 

published a book "Personal Identification". In this book, Wilder describes the anatomical formation 

of friction ridges. He also describes how random physical stresses and pressures, in addition to 

genetics, are responsible for friction ridge formation - "...all the infinite possibilities in the formation 

of the ridges are widely open in each individual case, so that it is quite safe to say that no two 

people in the world can have, even over a small area, the same set of details, similarly related to the 

individual units." Wilder's statement supports the primary basis for friction ridge identification 

being that fingerprints are unique. 

Harold Cummins (1929) 

A Professor of Anatomy and Assistant Dean of the School of Medicine at Tulane University in 

Louisiana. In 1929 Cummins published "The Topographic History of the Volar Pads in the Human 

Embryo". In this paper, Cummins describes the formation and development of volar pads on the 

human fetus. In 1943 he co-authored a book entitled "Finger Prints, Palms and Soles - An 

Introduction to Dermatoglyphics". He refers to his paper in this book and includes the following in 

Chapter 10 "Embryology": 

"All fetuses develop pads in conformity to the morphological plan. There is considerable variation in 

the time relations of the appearance and regression of pads... " (page 179) 

"The various configurations (of friction ridges) are not determined by self-limited mechanism within 

the skin. The skin possesses the capacity to form ridges, but the alignments of these ridges are as 

responsive to stresses in growth as are the alignments of sand to sweeping by wind or wave...Volar 

pads in the normal fetus are sites of differential growth, each being responsible for production of 

one of the local configurations comprised in the morphologic plan of dermatoglyphics. If a pad does 

not completely subside prior to the time of ridge formation, its presence determines a discrete 

configurational area." (pages 184-185) 

Alfred Hale (1952) 

Alfred Hale was an associate of Harold Cummins at Tulane University. In 1952 he published a paper 

called "Morphogenesis of the Volar Skin in the Human Fetus". His paper documents the actual 

stages of friction ridge development in addition to describing friction ridge skin formation on the 

human fetus. 

Michio Okajima 

Michio Okajima is a Japanese scientist who’s done thorough research regarding the skin. In 1976 he 

wrote “Dermal and Epidermal Structure of the Volar Skin” in which he describes the two rows of 

dermal papillae. The historical relevance of this research was confirming that the incipient ridges are 

permanent friction ridge structures.

Babler, Dr. William Joseph (May 24, 1949-present) 

Dr. Babler is recognized as the foremost authority in the structure and formation of friction skin. He 

is an Associate Professor of Oral Biology teaching human anatomy and embryology at Indiana 

University School of Dentistry. In addition, he served as the President of the American 

Dermatoglyphics Association, where he received their Distinguished Service Award in 2003. Dr. 

Babler has spent over 20 years researching the prenatal development of friction skin, writing 

numerous articles explaining his findings. He has confirmed many scientific theories about friction 

ridge formation as well as developed new theories. He has studied the effect of volar pad shape on 

resulting fingerprint patterns during fetal growth. This was presumed by Mulvihill and Smith but Dr. 

Babler did the research that confirmed their hypotheses. Dr. Babler has spent countless time 

educating forensic examiners and has continually made himself available as an educational 

resource. 

Ashbaugh, Staff Sergeant David R. (Retired) (Mar. 11, 1946-present) 

Staff Sergeant David Ashbaugh worked for the Royal Canadian Mounted Police, retiring in May of 

2004, in addition to being the Director of Ridgeology Consulting Services. He spent over 27 years 

doing extensive research on the scientific basis and identification process of friction ridge 

identifications. Among his long list of accomplishments he is credited with coining the term 

Ridgeology in 1983 and creating the terms level 1, level 2, and level 3 detail. He introduced the ACE- 

V methodology to the fingerprint field around 1980 and was a key witness for the Daubert Hearings. 

He sat on several committee boards and as well as serving on the Scientific Working Group on 

Friction Ridge Analysis, Study and Technology. In addition to publishing many papers on the 

identification process, in 1999 he authored the book “Quantitative-Qualitative Friction Ridge 

Analysis: An Introduction to Basic and Advanced Ridgeology”, which has become a fundamental and 

essential resource for all latent print examiners. Staff Sergeant Ashbaugh has received numerous 

awards and honors for his significant contributions to the science of friction ridge identification and 

is recognized as one of the leading experts in his field. 

Michael Kucken and Alan C. Newell, Department of Mathematics, University of Arizona 

Authors of “Fingerprint Formation” published in the Journal of Theoretical Biology, 2005. In this 

paper, Kucken and Newell offer the following hypothesis on the development of epidermal ridges: 

Kucken and Newell’s model confirms that: 

Primary ridges are formed as the result of a buckling process. 

Ridges form perpendicular to the lines of greatest stress as postulated. 

Volar pad geometry influences the fingerprint pattern as observed. 

The nervous system is involved in this process. 

Although ridges are the usual pattern, dots (hexagons) are another possibility. 

After the buckling instability has taken place and the ridge pattern is established, cell 

proliferations may increase the depth of the primary ridges.

Friction Skin Structure 

Skin is one of the largest organs of the body. It is recognized as an organ because it consists of 

several types of tissues that function together. In addition, it includes millions of sensory receptors 

and an extensive vascular network. The skin is a protective, pliable covering of the body, one that is 

continuously replaced. 

The skin over most of the body is relatively smooth. 'Friction Ridges', however, are found on the 

digits, palms and soles. They are called 'friction' ridges because of their biological function to assist 

in our ability to grasp and hold onto objects. They have been compared to fine lines found in 

corduroy, however unlike corduroy, ridges vary in length and width, branch off, end suddenly and, 

for the most part, flow in concert with each other to form distinct patterns. The ridge path can 

sometimes be quite fragmented...so much so as to show what appears to be individual ridge "units" 

present on the volar surface. There are approximately 2,700 ridge "units" per square inch of friction 

skin. Each ridge "unit" corresponds to one primary epidermal ridge (glandular fold) formed directly 

beneath each pore opening. 

Pore openings are present along the surface of the friction ridges. They are fairly evenly spaced due 

to the fact that one pore opening along with one sweat gland exists for each ridge "unit". 

Friction ridges are in their definitive form on the fetus before birth. Once this blueprint has been 

established, in the stratum basale (generating layer) of the epidermis on the fetus prior to birth, it 

does not change except for injury, disease or decomposition after death. Injury to the generating 

layer (Stratum basale) may affect the skin's ability to regenerate and scar tissue forms. 

Cross-section of Friction Skin 

Thick skin (which includes friction skin) 

has two principle layers: 

The Epidermis (E) is stratified 

(layered), squamous (flat) epithelial 

tissue 5 layers thick and... 

The Dermis is much thicker than the 

epidermis and consists of two layers - the 

Papillary layer (DPL) an area of loose 

connective tissue extending up into the 

epidermis as dermal pegs (DP) and the 

deeper reticular layer (DRL).

Friction Skin - Epidermal Layers: 

Stratum corneum - consists of 25-30 layers of 

stratified (layered) squamous (flattened) dead 

keratinocytes (skin cells) that are constantly shed. 

Stratum lucidum - is present only in thick skin 

(lips, soles of feet, and palms of hands). Little or 

no cell detail is visible. 

Stratum granulosum - 3-4 layers of cell thick 

consisting of flattened keratinocytes. At this level 

the cells are dying. 

Stratum spinosum - several layers thick, 

consisting mostly of keratinocytes. Together with 

the stratum basale it is sometimes referred to as the 

Malpighian layer (living layer). 

Stratum basale - a single layer of cells in contact 

with the basement membrane. These cells are 

mitotically active - they are alive and reproducing 

- the reason why it is often referred to as the 

generating layer. Four types of cells are present in 

this layer: 

Keratinocytes (90%) - responsible for waterproofing and 

toughening the skin 

Melanocytes (8%) - synthesize the pigment melanin which 

absorbs and disperses ultraviolet radiation 

Tactile cells - very sparse and function in touch reception 

Nonpigmented granular dendrocytes - cells that ingest 

bacteria and foreign debris. 

Friction Skin - Epidermis/Dermis Junction 

The primary function of the dermis is to 

sustain and support the epidermis. 

The papillary layer (DPL) is made up of 

connective tissue with fine elastic fibres. The 

surface area of this layer is increased by the 

dermal papillae (DP). These fingerlike 

formations greatly increase the surface area for 

the exchange of oxygen, nutrients and waste 

products between the dermis and the 

epidermis.

Friction Skin - Dermal Papillae 

The boundary between the dermis and epidermis is a point 

of potential weakness where the two tissues may be 

separated from each other. The fingerlike formations (or 

interdigitation) also serve to strengthen the 

epidermis/dermis junction. 

As one ages the dermal papillae tend to flatten and may 

increase in numbers. In this situation, each papilla appears 

to develop into a group...staying at the same overall size but 

individually much smaller. 

Sweat Glands 

Sweat glands, or eccrine glands, are found over the 

entire surface of the body except a few small areas. 

They are most concentrated in the palms and soles of the 

feet. The eccrine sweat glands in this skin section are 

well developed, and their ducts (dark staining in image) 

can be distinguished from the lighter staining secretory 

portions. 

They are simple coiled tubular glands; they consist of a 

highly coiled secretory portion deep in the dermis, and a 

relatively straight duct conducts the secretions toward 

the surface of the epidermis. Each duct opens in the 

centre of the ridge "unit" (cristae cutis). 

Eccrine sweat contains approximately 99% water and 

1% solids. The solids are half inorganic salt (mostly 

sodium chloride) and organic compounds (amino acids, 

urea and peptides). 

Other types of Secretory Glands (not found on Volar 

surfaces but may contaminate fingerprint residue or 

matrix) include sebaceous (oily secretions emptied into 

hair follicles) and apocrine secretions from specific 

sweat glands on the body. 

Incipient Ridges - An ‘immature’ friction ridge that is not fully developed. They may appear shorter and 

thinner in appearance than fully developed friction ridges. These ridges are also called interstitial, nascent, 

rudimentary and subsidiary ridges. They may or may not have fully developed pore formations. 

Friction Ridge Imbrication - Imbrication is observed on some areas of the volar surface where the friction 

ridges all tend to lean in the same direction. Friction skin is very flexible. This feature enhances the ability of 

the friction ridges to grip surfaces. When the friction ridges roll before slippage, this is also referred to as 

imbrication.

Identification Process / Ridgeology 

IMPORTANT- Recommended reading - Pages 87 – 148, Quantitative-Qualitative Friction Ridge 

Analysis, Ashbaugh 1999 

Ridgeology – term coined by David Ashbaugh in an article published in 1983 and can be defined as, 

“The study of the uniqueness of friction ridge structures and their use for personal identification.” 

Basis for Friction Ridge Identification: 

i. Friction ridges develop on the fetus in their definitive form before birth. 

ii. Friction ridges are persistent throughout life except for permanent scarring. 

iii. Friction ridge patterns and the details in small areas of friction ridges are unique and 

never repeated. 

iv. Overall friction ridge patterns vary within limits which allow for classification. 

Clarity – “How well the details from 3-D ridges that are reproduced in the 2-D print is referred to as 

the clarity of the print.” Ashbaugh, pg.93 It 1) dictates the level of detail available for comparison; 

2) dictates our level of tolerance for discrepancy; 3) may affect the size of the area of a friction ridge 

impression required to individualize; 4) is described according to the actual friction ridge formations 

observed during the friction ridge identification process such as – 

Level 1 – “patterns that may be repeated and therefore grouped” (First level detail does not have 

individualizing value and is described in degrees of rarity.) 

Level 2 – major ridge path deviations or “specific friction ridge path” (Second level detail has 

“individualizing power” and “its value is described in degrees of uniqueness”.) 

Level 3 – “intrinsic ridge shapes and relative pore locations” (“also described in degrees of 

uniqueness”) 

The Philosophy of Friction Ridge Identification: 

Friction ridge identification is established through the agreement of friction ridge formations, in 

sequence, having sufficient [observed] uniqueness to individualize. (See pages 97-103 for more 

detail) 

Friction Ridge Identification Scientific Methodology 

ACE-V 

A modified (or specialized) version of the scientific method of hypothesis testing. ACE-V was first 

used for physical evidence about 1960 & ridge detail about 1980. Inspector Roy A. Huber, RCMP, 

formulated the ACE-V process and Staff Sergeant David Ashbaugh, RCMP, popularized this process 

within the friction ridge identification field. 

A- Analysis: The unknown item must be reduced to a matter of properties or characteristics. These 

properties may be directly observable, measurable, or otherwise perceptible qualities. 

C- Comparison: The properties or characteristics of the unknown are now compared with the 

familiar or recorded properties of known items.

E- Evaluation: It is not sufficient that the comparison disclose similarities or dissimilarities in 

properties or characteristics. Each characteristic will have a certain value for identification 

purposes, determined by its frequency of occurrence. The weight or significance of each must 

therefore be considered. 

V –Verification: It (scientific method) insists upon verification as the most reliable form of proof. 

Insp. Roy Huber, Identification News Nov. 1962 

A- analyze - The first step, analysis, requires the expert to examine and analyze all variables 

influencing the friction ridge impression in question. This begins with an understanding of friction 

ridged skin and the transition of the three dimensional skin structure to a two dimensional image. 

When examining latent fingerprints, several factors must be accounted for and understood. Some of 

these factors are the material upon which the latent print has been deposited (substrate distortion), 

the development process(es), pressure distortion, and external elements (blood, grease, etc., 

different types of matrix distortion). Clarity of the print should be assessed and level of tolerance for 

discrepancies considered. The quantity and quality of the latent print ridges influences the 

examiners ability to perform the next phase. The conclusion of the analysis process is a 

determination as to whether sufficient information exists to proceed to the next phase. 

C- compare - The comparison process introduces the known exemplar with which the latent print is 

to be compared. At this point, there is also another analysis phase taking place. This analysis is of 

the known exemplar in an effort to determine the suitability for achieving the conclusion stated 

above. It is possible that the known exemplar may contain fingerprint images that are too heavily 

inked or smudged, and thereby unreliable, thus preventing a conclusive comparison. The 

comparison process begins with determining the general ridge flow and shape (Level 1 Detail) in an 

effort to properly orient the latent print with a corresponding area of the known exemplar 

fingerprints. This is generally followed by selecting key focal characteristics (Level 2 Detail), 

understanding their position, direction and relationship and then comparing this formation with the 

formations in the known exemplar. The quality and quantity of this information directly affects the 

ease or difficulty of this process. 

E- evaluate - The result of the comparison is the evaluation process or making a conclusion. The 

general fingerprint community refers to the conclusions drawn as being one of three choices. First, 

the two impressions (latent fingerprint and the known fingerprint) were made by the same finger of 

the same person. Second, the latent impression was not made by any of the fingers of the exemplar 

fingerprints. And third, a conclusive comparison could not be achieved, generally due to the lack of 

adequate clarity or the absence of comparable area in the known exemplar. In order to establish an 

identification decision, this process must insure that all of the fingerprint details are the same and 

maintain the same relationship, with no existing unexplainable differences. 

V- verify - The final process is verification. The general rule is that all identifications must be verified 

by a second qualified expert. This verification process by a second examiner is an independent 

examination of the two fingerprint impressions (latent fingerprint and known exemplar fingerprint) 

applying the scientific methodology of analysis, comparison and evaluation described above.

Latent Fingerprint Development Processes 

*****PLEASE REFER TO O.P.C. TRAINING MANUAL FOR HEALTH AND SAFETY RECOMMENDATIONS***** 

Online References – http://www.cbdiai.org/Reagents/main.html (Chesapeake Bay Division, IAI), www.redwop.com (Technical notes), http://www.rcmpgrc.gc.ca/firs-srij/recipe-recette-eng.htm 

(RCMP Forensic Identification Services) 

Porous Surfaces*** – Proper Development Sequence and Types of Chemical Processes (depending on the circumstances not all processes may apply).** All 

processes, however, are post visual and examination of inherent fluorescence by laser or alternate light source including UV. 

Development Techniques and ‘Basics’ of Processing 

Procedure 

Latent Print 

Development 

Colour 

Ridge Detail Visualized By 

Method to Record 

1. Iodine Fuming* 

Requires fuming chamber, ceramic or glass dish and 

heat source. 

Non-destructive technique 

Iodine fumes are more senstive to different latent 

residues than other methods. 

Clear to dark brown, 

often yellowishcoloured 

prints. 

Physical process by which Iodine vapours 

are absorbed by the fatty & oily 

components of print residue. 

Photograph at the greatest 

intensity of colour change. 

Developed prints tend to 

fade quickly. 

2. DFO (1,8-Diazafluoren-9-one) (1988) 

Specimen can be dipped or sprayed 

Must be dryed & placed in 100C (212F) oven for 10- 

20 minutes. 

Sometimes pink 

prints are 

visible. /Yellow 

fluorescence. 

Chemical reaction with amino acids & 

eccrine components of print residue &/or 

laser &/or F.L.S. @ 450,485,525,530 nm 

using orange goggles for white paper or 

laser or F.L.S. @ 570-590nm and red 

goggles for manilla envelopes, brown 

paper bags and cardboard. 

Illuminate with F.L.S. and 

photograph with orange or 

red camera filter. 

3. Ninhydrin 

Solution can be applied by dipping, spraying or 

painting. 

Specimen must be dryed and then heat and 

humidity (set @ 60-70%) can be applied to 

accelerate development of prints. 

Replaced Silver Nitrate (reacts with salt) process 

Magenta to deep 

purple. 

Chemical reaction with amino acids and 

proteins in eccrine components of print 

residue. Purple coloured compound 

produced known as ‘Ruhemann’s Purple’. 

Zinc chloride may be used to fluoresce, 

and enhance, the ninhydrin developed 

ridge detail. 

Photograph with a green 

filter.

4. Silver Physical Developer (Ag-PD) (1975) 

Pre-wash with maleic acid (10 min. or until bubbles 

disappear.) 

Specimen is immersed up to 20 min. & item s/b 

agitated (gentle rocking motion). 

Post-wash in 3 separate distilled water baths for ~ 5 

min. each before re-processing. 

Grey 

Chemical reaction with lipids, fats, oils 

and waxes in print residue. 

At present, no reagent has been as 

successful as the Ag-PD for visualizing 

the water-insoluable components of 

latent print residue (fats and 

oils/lipids, proteins) on paper. 

Photograph. 

* In their classes, the FBI is teaching a new method of using iodine. By mixing it with solvents and spraying it on papered or painted walls or paper 

documents, latent prints are being developed which last several hours. Therefore, photography of latent prints developed using Liquid Iodine need not be 

immediate. This method of spraying Liquid Iodine can be used at crime scenes if protective measures are taken. Iodine fumes are toxic & corrosive. Every 

precaution should be taken to avoid inhaling iodine fumes. A full-face, self contained breathing apparatus and protective clothing such as coveralls and 

gloves must be worn. CAUTION: The mixing and spraying of this solution must be done in a fume hood or while using a full-face breathing apparatus. 

** Physical Developer (used immediately after item has been dryed and fluorescence examination) is especially successful in developing latent prints on 

porous substrates that were previously wet. (Refer to Figure 5.8, pg.187, A.F.T. Flowchart for fingerprint visualization on paper and cardboard.) Sodium 

hypochlorite can also be used post-PD on porous, previously wet items. PD also works well on clay fire bricks, concrete, latex or rubber gloves, both sides 

of adhesive tape, rayon or nylon clothing, unfinished porcelain, unfinished wood and wooden knife handles. 

***Thermal and Carbonless Papers are used for many current business applications and therefore “a fundamental understanding of its chemical and 

physical properties is required to assist the examiner in deciding what possible method of chemical processing will not damage these specialty papers, 

while subsequently allowing for the development of quality friction ridge detail on their surface.” (Jon T. Stimac, Journal of Forensic Identification, Vol.53, 

Issue 2, 2003) Refer to separate article on Latent Print development on Thermal Paper in this study guide.

Non-Porous Surfaces – Proper Development Sequence and Types of Chemical Processes (depending on the circumstances not all processes may apply). All 

processes, however, are post visual and examination of inherent fluorescence by laser or alternate light source. 

Latent Print 

Development Techniques and ‘Basics’ of Processing Procedure 

Development 

Colour 


1. Cyanoacrylate Fuming (1977- used by Japanese Identification Service, Introduced in 1982 

by U.S. Army C.I.L. in Japan) 

Suspend items from upper area of fuming cabinet to allow entire surface to be exposed 

to the fumes. Two or three drops of liquid cyanoacrylate is placed into a small porcelain 

dish and placed into the fuming cabinet. Allow items to be exposed to the fumes for at 

least 2 hours until whitish-coloured prints appear. In addition, the process can be 

accelerated by use of a small battery-operated fan; heating apparatus such as a light 

bulb, hot plate or hair dryer; chemicals such as 0.5 N sodium hydroxide and cotton 

pads; vacuum acceleration procedure or a combination of the above (A.F.T. pg.118- 

120). (OPC – Process may speed up by addition of inhibitors, heat, increased air 

circulation, chemical reaction or reduction of atmospheric pressure.) 

Acceleration procedures all have the same 2 basic objectives: (1) accelerate the 

polymerization (solidification) process and (2) prolong the volatilization. 

Research suggests that prior to fuming the moisture in the latent print residue may be 

re-generated by exposure to acetic vapours, thus improving the quality. 

Has been successfully used on plastic, garbage bags, Styrofoam, carbon paper, 

aluminum foil, finished and unfinished wood, rubber, copper & other metals, 

cellophane etc. 

White 

Humidity is possibly a catalyst for 

ridge development (80% RH 

suggested by Home Office) 

Too much humidity can make 

impressions fragile but easier to 

see due to ‘frosted’ appearance. 

Fumes from the active 

cyanoacrylate ester polymerizes 

eccrine components of the print 

residue 

Impressions may be further 

enhanced by dusting with regular 

or magnetic fingerprint powders 

and /or post-cyano dye stains 

and UV light source or laser dyes. 

See OPC training manual for 

safety measures. 

2. Cyanoacrylate Dye 

Refer to separate table for appropriate choices. 

Dependent on type 

of dye used. 

UV, laser or alternate forensic 

light source. 

3. Powder 

Choice of powder will depend upon type and condition of substrate. Adherence to the 

impression and non-adherence to the substrate is the best test of powder efficiency. A 

secondary consideration in choosing the powder is colour. “As with any fingerprint powder, 

you should test on various surfaces to learn first-hand their strengths and weaknesses.” 

(OPC Training Manual) 

Powders can be divided into two general categories – Metallic and Granular.

Metallic powders – consist of very fine particles of various metals & should not be 

confused with magnetic powders. The most common contain aluminum, but copper, 

bronze and brass are also available, both separately and in combination. Metallic 

powders have the best adhering qualities of any powders commonly in use and should 

be given 1 st consideration. 

Granular Powders – appear like miniature chunks of crushed rock when viewed under a 

microscope. It can be used on windows, counter-tops, television sets, metal file 

cabinets, painted doors, broken glass and metal window frames and; painted surfaces, 

glass windows and mirrors in recovered stolen vehicles. 

Magnetic Powders– Magnetic powders are generally made by mixing iron grit with 

either aluminium or copper flake powder. Magnetic powders generally develop better 

latent prints on shiny magazine covers or boxes with a coated surface and ceramics* 

rather than regular powders. Some plastic materials, such as food storage containers 

and plastic baggies are choice surfaces for magnetic powders. (*IAI,Vol.53,No.2) 

“They are quite useful when examining vinyl surfaces, such as automobile interiors, 

because they avoid the build up of static caused by a fiberglass brush.” (OPC Training 

Manual) 

Aluminum-based – 

light grey, 

sometimes sparkly. 

Regular – black, 

silver/gray, white 

and Bichromatic 

(appear light on 

dark surfaces & 

dark on light 

surfaces) . 

Magnetic – 

available in same 

basic colours as 

regular powders 

including 

fluorescent. 

Particles stick to regular 

fingerprint matrix & due to 

electrostatic charge built up from 

the brushing action when using a 

fibreglass brush. E.C. may cause 

adherence problems on some 

plastic surfaces or ‘tacky’ 

surfaces such as greasy windows. 

Powder clings to moisture, oil 

and other components of print 

residue creating a contrast 

between the print and the 

substrate. Granules do not 

adhere as strongly to the 

substrate as the metallic platelets 

and readily fall off. These 

powders also tend to act as 

abrasive grit and may destroy 

print – care must be taken during 

application. 

Application of magnetic powder 

requires the use a magnetic 

wand. 

Because of the probability of the 

wand magnetizing steel objects, 

they are not the first choice when 

examining metallic exhibits.

Fluorescent Powders – Some substrates have a confusing , multi-coloured background 

pattern from which it is difficult or impossible to photographically separate the 

impression. Use of fluorescent powder will allow photography of the impression using 

UV techniques with little or no background interference. 

It is recommended that the piece of evidence be treated with glue fumes initially before 

application of fluorescent powders. It is better to "underfume" than to "overfume" as 

the fluorescent powders adhere to the glue residue. If the entire surface is heavy with 

white residue, the powder may adhere to the entire surface and it will glow so strongly 

that the fine details in the latent prints may be lost. Glue-fuming in a vacuum system 

causes the glue to adhere to latent print ridge details and prevents the glue residue 

from adhering to the entire surface. 

Fluorescent powders are very fine powders with a Lycopodium base. It has been 

reported that they seem to be best for wooden surfaces, such as rifle stocks and wood 

paneling. Whenever liquid dye staining might damage the object being examined or in 

field work situations where liquid dye staining is a problem, fluorescent powders can be 

used instead. 

Fluorescent - The 

goal is to choose 

the colour of 

powder that will 

fluoresce at a 

different 

wavelength than 

the background. 

Fluorescent powders have the 

same powdering characteristics 

as white powder. 

It is recommended that a feather 

duster be used to apply 

fluorescent powders under a UV 

light source for best results. 

** Caution – Proper UV eye & 

skin protection must be worn at 

all times. 

Fluorescent powders work well 

under argon-ion, copper-vapor 

and Nd:YAG lasers, along with 

Forensic Light Sources and longwavelength 

ultraviolet lights.

Post–Cyanoacrylate Dye Stains 

Ardrox 135D Liqui-Drox (not in OPC notes) Rhodamine 6G Basic Red 28 Brilliant Yellow 40 

Basic Procedure 

(O.P.C., A.F.T. pg.122 

& RCMP) 

1) Swab a liberal amount onto the 

exhibit with a Q-tip or wad of cotton. 

2) NB - Let dye dry completely 

3) Rinse object under cool running 

water to remove excess dye and allow 

exhibit to dry; 

(Alternate – use a 2% solution in 

alcohol. Mix 10ml Ardrox in 990 ml 

methanol; immerse or spray exhibit; 

rinse & air dry.) 

Used to enhance latent prints 

developed on adhesive and 

non-adhesive sides of tape. 

Solution of Ardrox,Liqui-Nox & 

distilled water is brushed onto 

tape (after non-adhesive side 

has been fumed) and left for 

appox. 10 seconds, rinsed and 

air dried. 

Can be followed with R.A.M.* 

dye stain. 

- Stock solution made 

with 1g dye with 1 litre 

methanol. 

- Working solution- 

30ml stock : 1 litre 

methanol 

- Immerse or spray 

exhibit with solution. 

- Rinse in methanol and 

air dry. (Also a no rinse 

method used by OPP.) 

- Can be followed with 

R.A.M.* dye stain. 

Applied by either 

dipping or spraying. 

Can be followed by 

R.A.Y.* dye stain. 

Allow item to air dry 

then rinse with 

distilled water and 

allowed to air dry 

again. 

- Dissolve 2g brilliant 

yellow in 1 litre ethanol 

- Pour clear solution 

(undissolved dye) in a 

separate container. 

- Immerse or spray 

exhibit with solution. 

- Rinse and air dry. 

- Can be followed by 

R.A.Y.* dye stain. 

Latent Print 

Development Colour Yellow Fluorescence Yellow Fluorescence Orange Fluorescence Orange Fluorescence Yellow Fluorescence 

Ridge Detail 

Visualized By 

Recording Method 

Long wavelength UV light 300 nm – 

365 nm or Forensic Light Source at 435 

nm – 480 nm. 

Use yellow or orange-coloured 

goggles. 

NOTE- If there is too much background 

fluorescence use alternate. 

Photograph using a 2-A haze, yellowcoloured 

or 515 bandpass filter. 

Long wavelength UV light. 

Use yellow or orange-coloured 

goggles. 

Photograph promptly – the ridge 

detail will begin to fade after 12 

hours. Photograph using an UV 

blocking 2A filter 

Laser (488nm – 514nm) 

or Forensic Light Source 

at 450nm to 540 nm. 

Use orange or redcoloured 

goggles. 

Photograph using an 

orange or bandpass 

550 barrier filter. 

Laser or Forensic Light 

Source at 470 nm to 

550 nm. 

Use orange-coloured 

goggles. 

Photograph using 

orange or bandpass 

550 barrier filter 

1) Long wavelength UV 

light ~365nm & UV 

protection goggles 

(least preferred) 

2) F.L.S. at 450 to 

485nm & yellowcoloured 

goggles. 

Photograph using a 

yellow coloured or 550 

bandpass filter. 

Additional Notes: 

Various different dyes are used to post-treat cyanoacrylate-developed prints because they have different absorption and emission maxima and thus offer versatility in 

enhancing latent fingerprints on various types of surfaces that can themselves be multicoloured and have varying lumines cence characteristics. Dye mixtures increase 

versatility through intermolecular energy transfers that enable the examiner to take advantage of one dye’s absorption maximum while monitoring luminescence at 

another dye’s emission wavelength. (A.F.T. pg.123) 

Some researchers advise to allow the cyanoacrylate-developed prints to "sit" overnight prior to applying the dye stain. 

*R.A.M. - Rhodamine 6G, Ardrox, MDB; R.A.Y. – Rhodamine 6G, Ardrox, Basic Yellow

Wet, Non-Porous & Porous Surfaces – Types and details of chemical processes in proper development sequence – depending on circumstances not 

all processes may apply. All processes, however, are post visual and examination of inherent fluorescence by laser or alternate light source. 


1. Small Particle Reagent (S.P.R.) (a.k.a. Powder Suspension) 

A reagent for latent print processing of non-porous items that 

became wet after the impressions were deposited. Suggested for 

use on items where latent print powders are ineffective. Not 

suggested for items contaminated with greasy substances. 

Can be used post-cyanoacrylate when dye stains are ineffective. 

The active ingredient (Molybdenum disulfide) is applied either by 

spraying or dipping. 

Rinse with tap water & dry at room temperature. Prints are more 

visible when they are dry. 

Photograph any developed detail and then you may try lifting the 

dried print. 

Latent Print 

Development 

Colour 

Dark grey 


The SPR technique relies on the adherence of fine 

particles suspended in a treating solution to the fatty or 

oily constituents of latent fingerprint residue. 

(Formulated mid 1980s) Accordingly, it may be regarded 

as belonging to the same family of methods as powder 

dusting. SPR consists of a suspension of fine 

molybdenum disulfide particles in detergent solution. 

2. Silver Physical Developer (Ag-PD) 

First formulated in 1975 by the British Home Office Police S.D. 

Branch. 

PD is a surfactant-stabilized solution containing silver ions, a 

ferrous/ferric redox system, a buffer (citric acid) and detergents 

in an aqueous solution. 

PD is used for the development of lipid type (oily,greasy) 

impressions on porous surfaces. (OPC) 

PD works well on clay fire bricks, concrete, latex or rubber gloves, 

both sides of adhesive tape, rayon or nylon clothing, unfinished 

porcelain, unfinished wood and wooden knife handles. 

(A.F.T.pg.136) 

Dark Grey 

It’s water-based and thus it visualizes the waterinsoluable 

portion of the latent print residue. These 

components include fats and oils (lipids) but also waterresistant 

proteins, lipoproteins, and even water-soluable 

components (amino acids, proteins, urea, salts etc.) that 

get trapped in the lipids as they “dry” and harden 

through oxidation.

3. Modified Physical Developer (MMD) (Porous & non-porous 

surfaces.) 

New procedure reported in 1989 involving treating the item with 

a colloidal gold sol’n and then a weak (modified) Ag-PD sol’n. 

This technique was called “multimetal deposition” (MMD) 

Works well with many surfaces and materials such as floppy disks, 

adhesive tapes, metals, papers, Styrofoam, credit cards and glass. 

It can also be used for specimens that have already been treated 

with ninhydrin. (AF.T. pg. 138-140; pg.262-266) 

Colloidal gold particles (in a sol’n pH ~3) are highly 

negatively charged & thus bind to amino acids, peptides 

and proteins in fingerprint residue. The bound colloidal 

gold provides a nucleation site around which silver 

precipitates in the second incubation step. (“One speaks 

of silver amplifying the gold image. A.F.T. pg.263) 

4. Sudan Black 

A dye stain technique for use on non-porous wet items. 

It is considered less sensitive than other wet item techniques in 

use. 

Sudan black is considered useful for those wetted items whose 

surfaces are contaminated with substances such as grease, 

beverages and food-stuffs. 

May be used as a post-cyanoacrylate developer, and is especially 

useful for post-cyanoacrylate staining on the inside of latex 

gloves. 

Dark Blue 

Dark blue-stained ridge detail is revealed upon a tap 

water rinse and the item allowed to air-dry. 

5. Oil Red O 

A lipid-specific dye stain technique for use on porous items which 

have become wet. Research has shown that Oil Red O can be 

superior to Physical Developer to develop latent fingerprints on 

thermal paper and standard white paper. Fewer immersion steps 

and less need to avoid chloride contamination are benefits using 

the Oil Red O reagent. 

Red 

Sensitive to lipid components. 

Visible chemical/stain reaction. 

Image enhancement methods can be used to improve the 

contrast between the stained ridge detail and the pink 

background.

Bloodstained Specimens, non-porous or porous substrates. 

If the item is wet allow to dry at room temperature. All development techniques are post visual examination & examination of inherent 

fluorescence by laser and alternate light source and UV light. 


Aqueous Leucocrystal Violet (L.P.Co. Technotes & OPC Notes) 

Aqueous Leucocrystal Violet (LCV) can be applied to porous or 

nonporous surfaces, such as paper, metal, plastics or glass. 

It is best applied by either submersion or by washing the solution over 

the surface in question. It is NOT recommended to spray Aqueous 

Leucocrystal Violet except in the case of carpeting to observe shoeprints 

or other marks in blood. The development will begin to occur within 30 

seconds. Then, blot with paper towels, tissues or even toilet paper if that 

is all that is available, to remove the excess reagent. Begin by spraying 

lightly with a fine mist to avoid overdevelopment. 

Sequential Processing 

The first process suggested is to use fluorescent powders (choose the 

color most appropriate for the background fluorescence). Then use 

Aqueous Leucocrystal Violet and then, Physical Developer. The Physical 

Developer may or may not enhance the bloody latent prints, but it may 

develop other latent prints. Each chemical reacts with different 

components of the blood residue. 

Latent Print 

Development 

Colour 

Dark Violet 


It will not stain the normal constituents 

found in latent print residue so it should only 

be used in the case of blood-contaminated 

latent prints to be successful. This solution is 

an indicator for blood, however, it may react 

with other substances not specific to blood. 

Photography of latent prints developed with 

Aqueous Leucocrystal Violet should not pose 

any problems if the surface background is a 

light color. If the surface is a dark color but 

will fluoresce, it may be beneficial to use 

fluorescence examination to enhance the 

photographic contrast. One recommended 

method is to use a Forensic Light Source set 

between 550 and 600 nm, view with red 

goggles and photograph with a dark red 

filter. 

Amido Black (Methanol Based or an alternate aqueous-based formula.) 

OPC Notes 

Use if LCV is not available or post-LCV. (A.F.T. pg.143-144) 

Methanol-based solutions may give sharper ridges especially on nonporous 

surfaces but may damage some surfaces. 

Known to be effective on plastics and cotton sheets. (pg.145) 

Deep Blue 

General Protein Stain* 

Dye solution binds to protein molecules in blood 

and yields a coloured complex. 

Hungarian Red (OPC Notes) 

Spray or immerse exhibit for approximately 1 minute 

Deep Magenta 

General Protein Stain* 

Dye solution binds to protein molecules in blood 

and yields a coloured complex.

Leucomalachite Green (RCMP) 

extremely sensitive to the presence of blood and will yield positive 

results with dilutions of blood as low as 1 part in 1 million. 

Green 

Leucomalachite green reacts with the protein in 

blood to produce a green color. 

Cyanoacrylate fuming – non-porous substrates 

Prior to fuming, the moisture in the latent print residue may be regenerated 

by exposure to acetic vapours, thus improving quality. 

Research has shown that applying CA before using a general protein 

stain achieved no improvement in the enhancement of bloody prints. 

With glass and metal surfaces, CA is harmful for further processing with 

Coomassie Blue, Crowle’s reagent, and amido black dye. 

White 

Fumes from the active cyanoacrylate ester 

polymerizes components of the print residue. 

Post-cyano dye stains &/or regular or magnetic 

powders are used to further enhance the 

developed prints. Refer to separate table for a list 

of possible dye stains and appropriate forensic 

light sources. 

Titanium Dioxide (OPC Notes) 

6 or 7 spray applications with continuous agitation of mixture in bottle. 

Leave for 30 seconds. 

Methanol rinse applied in same manner as working solution. 

Allow to air dry. 

White 

For developing bloody prints on dark surfaces. 

Acid Yellow (OPC Notes) Yellow View when dry using alternate light source at 

450nm and orange goggles. 

Luminol (OPC & RCMP Notes) 

An alkaline solution of Luminol will oxidize in the presence of an 

oxidizing agent such as hydrogen peroxide or sodium perborate and a 

Hematin-catalyzed peroxidase system, such as that found in blood. 

This oxidation 

reaction produces a 

blue 

chemiluminescence. 

1. Darken crime scene. 

2. Set-up camera for photography. 

3. Wearing face shield and officer protection 

suits spray area with luminol solution. 

4. Immediately photograph 

chemiluminescence. 

Repeat spraying step if chemiluminescence 

fades. Note - False positive reactions are 

common.

* General Protein Stains: 

A disadvantage of techniques involving the dye solution staining technique is that articles containing latent prints have to be directly immersed in the 

solution. To prevent the bloodstain from dissolving in the solution, the article has to be baked in an oven at 100 C for 3 to 5 min to denature and fix the 

bloodstain on the surface. In addition, most dye solutions are made with organic solvents or are soluble under acidic conditions, making them unsuitable 

for use on certain surfaces. Hunter described successful development of an identifiable print on gloves after 25 years with Coomassie blue. 

The Fingerprint Development Handbood (PSDB) suggests that fingerprints in blood on non-porous surfaces, depending on the appearance of the prints, 

should be processed using fingerprint powders first, followed by ninhydrin, amido black and then PD.(pg.43) 

As always, it is suggested to photograph any latent prints developed with each process before treating the evidence with a new process. 

Note: It is known that when liquid blood coagulates (clots), the serum and blood cells separate. A straw-coloured liquid, the serum fraction, forms 

around the solid red mass, the blood cell fraction. If a finger touches coagulated blood that has not dried and then deposits a print on a surface, the 

resulting “bloody” fingerprint may be composed mainly of serum, mainly of coagulated red cells, or of both. These possibilities have significant 

implications for choosing the optimal method of bloody fingerprint enhancement. The best method for a particular bloody print should be based on an 

understanding of the nature of the bloody print and the mechanism of the transfer. (A.F.T. pg.146)

Additional Latent Print Development Processes 

Latent Print Examination of Skin 

by Ed German 

updated 10 July 2001 

a 

Because the same chemicals naturally deposited in latent prints are also present on the rest of the body's skin, successful latent print detection on skin 

normally involves a contaminant of some type (blood, dirt, lipstick, wet paint, vaseline, etc.). I recommend detectives look carefully at the victim's skin 

for any obvious "finger or palm ridge detail" (not just red marks on the skin). Success may come in the form of just having your evidence technicians 

take pictures of visible prints. 

If the victim is wearing red or orange lipstick and the suspect put his hand on her (or his) mouth, you will have good potential for examining the live (or 

deceased) victim's body (and clothing, bed sheets, etc.) with an alternate light source or portable laser (viewing through AR goggles - typically orange) to 

see latent prints which are invisible in room light/daylight but glow brightly when excited with relatively monochromatic blue-green light. Red and 

orange lipstick contain dyes very similar to those we use in crime labs to "tag" faintly developed super glue fumed prints and make them glow brightly. 

Two schools of thought for developing latent (invisible) prints 

There are two schools of thought insofar as how to develop invisible (latent) friction ridge prints which may be on a body. They are the "lift transfer" 

method and "direct super glue fuming" method. It is possible to use both methods (lift transfer, then fuming) on cadavers, though most experts tend to 

use only one or the other. (Note – Per OPC Training Manual – “Magnetic powders have been used with limited success on cadavers in homicide cases.” 

Lift transfer method 

Known for decades as the "iodine fuming silver transfer lift" method, the development of fatty/waxy contaminant latent prints transferred from skin 

onto a nonporous surface is still quite popular... but now with improved transfer mediums and post-transfer development. Since the 1990's, super glue 

development of the transferred prints has generally replaced old fashioned exposure of silver plates to actinic lighting for developing impressions. 

Latent Print Examiner William Sampson from Florida has contributed to much of the modified transfer lift research for skin. 

For live victims, a piece of black plastic (such as RC photo paper developed as black) can be held against areas suspected as possibly bearing latent 

(invisible) prints. Other nonporous surfaces such as a mirror, glass, or metal plate may be used instead of photo paper. Some examiners use a sponge or 

soft pad between their hand and the photo paper to improve contact the victim's skin. 

Hold the transfer surface against the skin for 15 to 20 seconds. The nonporous transfer surface should then be super glue fumed to develop latent prints 

which may have transferred. There is no need to wait for "water content drying" because any water in the latent print residue will aid polymerization 

with super glue fumes. 

After super glue fuming, further development of the nonporous transfer surface should include luminescent dye stain, laser or alternate light source 

excitation, and (lastly) powder rubbing.

For deceased victims, the body's skin surface should be between 72 and 80 degrees for optimal fatty/waxy impression transfer. Warm the lift card or 

other transfer medium with a portable hair dryer just before lifting (warming it to above 86 degrees fahrenheit has been suggested by some 

researchers). 

Some examiners use porous white paper (such as adding machine tape) for lifting impressions... the main difference being the post-transfer 

development methods. DFO, ninhydrin and then PD is one of the most sensitive sequences for processing paper. 

Super glue fuming cadavers 

Ivan Futrell and Tim Trozzi of the FBI's Latent Fingerprint Section worked with Art Bohanan of the Knoxville, Tennessee Police Department in performing 

some of the most significant research of the 1990's on super glue fuming bodies. 

Ideally the body should not be refrigerated prior to fuming because moisture can destroy impressions that might otherwise be developed. If already 

refrigerated, permit all condensation moisture to evaporate upon removing the body from the cold locker/drawer. 

An airtight plastic tent can be assembled over the body and fuming is accomplished using heat acceleration (coffee cup warmers) accompanied by a 

small, battery powered fan to help with even fume distribution. The fan should be battery powdered because sparks from a 110V electric fan motor 

may pose a fire hazard in a confined fuming chamber. 

A test strip of plastic or aluminum bearing a "test" latent print should always be fumed with the body. If the test impression has developed well (clearly) 

then you are ready to dust the body using a contrasting color powder. Feather dusters with fluorescent powders are sometimes successful; but black 

magnetic powder is used more often. Black magnetic powder usually "paints" the skin less, doesn't require a laser or alternate light source and is easier 

to photograph. 

Portable fuming devices are commercially available and can be used to develop prints in as little as 10 to 15 seconds of fuming for each small area 

examined.

Developing Latent Prints on Tape – adhesive side. 

All processes are post visual and examination of inherent fluorescence by laser and alternate light source. Selection of development 

process is primarily dependent upon an attempt to produce the greatest contrast between the surface and the print. 

Latent Print 

Development Techniques and ‘Basics’ of Processing Procedure Development Colour 


Crystal / Gentian Violet 

Immerse tape in (adhesive side down) working solution for about 

10 seconds. 

If impression is weak, repeat the treatment 

Rinse tape in a dish of cool water or under a running tap for 

about 10 seconds 

Allow tape to dry; photograph 

Sticky-side Powder (Formulated in 1991 in Japan) 

can be applied as a thin paste with a brush or as a shallow bath 

in which the tape is immersed, sticky side uppermost. 

Purple 

Black 

Protein dye that stains epithelial skin cells, sebaceous 

lipids and proteins. 

Use F.L.S. at 525,530 & 570 nm & red goggles OR 

FLS at 485 or 450 nm and orange goggles. 

Photography then place tape, adhesive side down, on a 

sheet of clear acetate for protection 

See OPC notes for transfer of prints from dark tape (i.e. 

very little contrast between impression and substrate. 

Visible chemical reaction with sebaceous & lipid 

components + laser or alternate light source. (Also 

suggested that it is actually a physical process – SSP fill in 

the contours of the moulded impression left on the tape.) 

Liqui-Nox (Alternate Black Powder) 

Developed by Robin Bratton & Jeff Gregus of Michigan State 

Police 

Black powder + Liqui-nox detergent 

Works similar to Sticky-Side Powder 

Solution is ‘painted’ onto the adhesive side with a camel hair 

brush then rinsed under a slow stream of running water. 

Ash Gray Powder 

Bonnie Martin of Oregon State Police modified the Sticky-Side 

Powder formula using white or ash gray powder in place of S.S. 

powder for better results against a black substrate. 

Black 

White to gray 

It is a relatively slow process & the resulting impressions 

may be faint. This process works best on light-coloured 

tape. 

Visible chemical reaction with sebaceous & eccrine 

components of fingerprint residue + laser or alternate 

light source. 

“In comparison testing with both the Sticky-side powder 

and Crystal Violet methods the black powder/Liqui-Nox 

method was found to be superior. Note – Liqui-Nox is a 

product of Fischer Scientific. It is a specially prepared 

detergent for laboratory use having no additives that may 

leave residues on glassware that could affect chemical 

processes.” (OPC Training Manual) 

Visible chemical reaction + Laser or alternate light source.

Titanium Dioxide (prints develop on non-adhesive and adhesive 

sides) 

White 

Chemical reaction – see separate article in this study 

guide for additional information. 

From OPC Notes for developing prints on “Balled Tape”… 

Tape may be separated for examination by heat, freezing or solvent. 

1) Heat method – Use hair dryer at low or medium setting 

2) Freezing method – Place tape in freezer until frozen solid or use a 

pressurized can of air sprayed directly onto the tape. 

3) Solvent method – Use “Shandon Xylene” developed by the U.S. Army 

Criminal Investigation Laboratory. Under a ventilation hood/fuming 

cabinet & using gloves & eye protection, hold the tape with tweezers and 

use an eye dropper to apply very small amounts of the solvent to the 

tape at the line of adhesive. This method has also been effective in 

removing adhesive tape from paper or cardboard. 

Caution - Impression may be damaged from transfer of 

cells during separation of tape. 

Using the solvent method, fingerprints have been 

developed not only on the tape but also on the paper 

from which it was removed. The tape was examined 

using Crystal Violet and Ninhydrin was used on the paper. 

Developing Latent Prints on Tape – non-adhesive side. 

Proper development sequence and types of chemical processes – depending on the circumstances not all processes may apply. All processes, however, 

are post visual and examination of inherent fluorescence by laser and alternate light source. 

Latent Print 


Development Colour 


Cyanoacrylate Fuming 

To protect adhesive side, place tape on a piece of clear acetate before CA. 

Vacuum Metal Deposition (see page ) 

White 

Fumes from the active cyanoacrylate ester 

polymerizes eccrine components of the 

print residue. Post-cyano dye stains &/or 

powders are used to further enhance the 

developed prints. Refer to separate table 

for a list of possible dye stains and 

appropriate forensic light sources. 

Powder 

Dependent on choice of 

colour. 

Contrast made between powder colour and 

substrate.

Development of Latent Prints on Thermal Paper - Manual of use for ThermaNin 

Introduction 

Thermal paper, once mainly used as fax paper only, is now used in many applications. These days it is used in ticket dispensers for giving out 

queue numbers or parking tickets, in label printers, and printers for point-of-sales receipts at retail shops like supermarkets. 

Thermal paper turns black on application of heat (as in the printer) but also on contact with polar solvents like alcohols, acetone, ether, 

ethyl acetate etc. The regular solutions of fingerprint reagents like ninhydrin and DFO are either based on a polar solvent (ninhydrin in ether 

or acetone for example) or rely on certain amounts of these polar solvents to dissolve them when used in an apolar bulk solvent like 

petroleum ether or heptane. 

These solutions have a detrimental effect on thermal paper: on application the paper surface turns dark grey or black thereby obscuring any 

fingerprints that may subsequently develop. 

There are only a few techniques known for developing fingerprints on thermal paper: 

 

 

 

 

1,2-IND (as a 2 g/l solution in HFE-7100 containing 7% ethyl acetate) has been reported to develop fingerprints without darkening 

the top (active) layer of the thermal paper (John Stimac, Journal of Forensic Identification, 2003, 53(3), 265-271). For finding and 

photographing the developed prints a Polilight or similar light source is needed. 

DMAC (dimethylaminocinnamaldehyde) fumes react with fingerprints on thermal paper (see e.g. Brennan et al., Journal of Forensic 

Identification, 1995, 45(4), 373-380). The fluorescence of any developed prints can be photographed with green light (Polilight, 

around 530 nm). 

Exposure to the fumes of concentrated hydrochlorid acid was reported to develop prints on the top layer of thermal paper (Broniek, 

Knaap, Journal of Forensic Identification, 2002, 52(4), 427-432). It will not develop prints on the back of thermal paper. 

Treatment with a regular ninhydrin solution and after allowing ample time for development of fingerprints, rinsing the paper with an 

excess of acetone to remove all the text and/or grey-black stains.

These techniques may not be appropriate, or the additional equipment needed not available. 

Japanese researchers have published that hemiketals of ninhydrin, obtained by exchanging the water molecule in ninhydrin [also known as 

1,2,3-indantrione monohydrate] for an alcohol, are soluble in apolar solvents like petroleum ether without the need for addition of polar 

solvents. The solutions were reported to develop fingerprints on thermal paper, without darkening of the surface. 

Such a product (named ThermaNin) is now available from BVDA. 

To our knowledge, the effectiveness of the different techniques has not been compared. 

How does ThermaNin work 

ThermaNin will not develop any fingerprints by itself. The process relies on the fact that after application of its solution to paper, ThermaNin 

will readily convert to ninhydrin and the alcohol upon contact with water present in the paper or in the atmosphere. This conversion can be 

detected from the weak odor of the alcohol that will be given off by the paper afterwards. The ninhydrin will then be available to react with 

any fingerprint residue in the paper. The ninhydrin will not dissolve in petroleum ether, so the paper can be dipped twice (with a certain 

waiting time in between, to allow for the conversion of the ninhydrin hemiketal to ninhydrin and alcohol) to increase the ninhydrin 

concentration in the paper.

Manual of use 

Due to the sensitivity of ninhydrin hemiketals (like ThermaNin) towards water, their solutions in petroleum ether cannot be stored long 

without degrading the performance. A working solution should be used soon, at least within 1-3 weeks. Therefore, we cannot supply 

working solutions, they should be made fresh when needed. The ThermaNin crystals that we supply are fairly resistant to atmospheric 

humidity and have no apparent shelf life when stored in tightly sealed containers. 

A working solution that takes not too long to prepare, by dissolving the ThermaNin powder in petroleum ether/pentane or heptane by 

shaking (for 5-10 minutes), contains 4 gram per liter (or 0.4 gram per 100 ml). Slight warming of the solution (till around 30-40° C) will aid 

the dissolution of the ThermaNin powder considerably. 

German researchers at the BKA in Wiesbaden found that for dissolving, application and storage of working solutions of ninhydrin hemiketals 

either plastic or aluminium containers should be used, with a strong preference for aluminium. Generally speaking petroleum ether etc. 

diffuses out of plastic bottles and water in, aluminium does not have this problem. 

In glass bottles the shelf life of the working solutions is drastically shortened. This is probably due to the small amount of water adhering to 

the walls and the slightly acidic nature of the glass surface (accelerates the reaction between water and ThermaNin). 

Development of the fingerprints can be done in the usual manner: at room temperature, in the dark and elevated humidity (around 80% is 

preferred). Because of the nature of thermal paper heating of the paper to accelerate development of the prints is not possible: the paper 

will turn dark. 

Because of the sensitivity of the paper for polar solvents, treatment of the thermal paper with zinc chloride is not an option either. 

Safety 

On contact with water ThermaNin will readily fall apart in ninhydrin and alcohol. Therefore, the safety characteristics of the product can be 

judged from those components. Ninhydrin is considered harmful if swallowed and irritating to eyes, skin and respiratory system; the alcohol 

as a skin and eye irritant. The precautions taken when working with ninhydrin (protective clothing, gloves, safety glasses when working with 

the solutions) will be sufficient for this product too.

VACUUM METAL DEPOSITION 

Fingerprint contamination on a surface can hinder the deposition of metallic films following metal evaporation under vacuum. This 

phenomenon has been known for a long time but it is only recently that it has been applied to the detection of latent fingerprints. It is now 

accepted that Vacuum Metal Deposition (VMD) is an extremely sensitive and useful technique for fingerprint detection on a variety of 

surfaces and it may be employed in conjunction with other development techniques, such as cyanoacrylate. Unfortunately, a large VMD 

units are prohibitively expensive for most laboratories, and significant experience is required in order to obtain the best results from this 

technique. 

Gold is evaporated under vacuum to form a very thin layer of metal on the surface under examination (this layer is invisible to the naked 

eye). A second layer of zinc or cadmium (the latter is rarely used because of its toxicity) is deposited in the same manner. The gold film is 

uniformly deposited across the surface of the sample and penetrates the fingerprint deposit. The zinc is deposited preferentially on the 

exposed gold but does not penetrate the fingerprint deposit - the ridges are therefore left transparent while the background becomes 

plated with a layer of zinc. Excellent fingerprint detail can be obtained in this way with the best results on surfaces such as plastic and glass. 

Fresh fingerprints, less than 48 hours old, have also been developed on cloth and banknotes using this technique. See below. 

Principle of fingerprint development by VMD 

Vacuum Metal Deposition can sometimes reveal fingerprint detail when all other techniques have failed. Excellent results have been 

obtained using metal deposition after cyanoacrylate development followed by luminescent staining. 

Vacuum metal deposition (VMD) is a well-established technique that can be used for the development of latent fingermarks on a range of 

polymer surfaces, including polyethylene (PE) bags exposed to harsh environmental conditions. The technique has also proved to be 

effective on difficult semi-porous surfaces such as the polymer banknotes in circulation in Australia and in an increasing number of other 

countries.

Reagent Reacts With Type of substrate 

IODINE FUMING 

Physical process - iodine 

fumes adhere to 

sebaceous components 

of latent print residue. 

Porous or 

Non-Porous 

Resultant 

Colour 

Yellow to Brownishcoloured 

prints. 

DFO 

Chemical reaction with 

Amino Acids 

Porous 

Pink or Fluorescent 

Yellow 

NINHYDRIN 


Amino Acids 

Porous 

Magenta to Deep Purple 

PHYSICAL DEVELOPER 


lipids, fats, oils and 

waxes in latent print 

residue. 

Porous, including 

previously wet porous 

items. 

Grey 

SILVER NITRATE 


salts in latent print 

residue. 

Porous 

Dark brown or black. 

CYANOACRYLATE FUMING 

Chemical reaction. 

Polymerization of latent 

print residue. 

Non-porous 

White. 

Enhance with fluorescent 

dyes & view under UV, 

laser or FLS. 

POWDERS 

Granular, metallic, 

magnetic, fluorescent 

Physical process- powder 

adheres to moisture and 

lipid components. 

Non-porous and 

porous. 

Variety of colours - 

choose to create the best 

contrast with substrate. 

SMALL PARTICLE REAGENT 

Physical process - 

adheres to sebaceous 

components of latent 


Wet, non-porous. Can 

be used post-CA 

Grey 

VACUUM METAL 

DEPOSITION 

Deposition of thin metal 

films onto fatty 

components of latent 


Non-porous, plastic 

and older items. 

Grey 

SUDAN BLACK 

A dye which stains fatty 

components of 

sebaceous sweat. 

Greasy, non-porous. 

Blue-Black

Reagent Reacts With Type of substrate 

AMIDO BLACK 


protein in blood. 

Bloodstained 

specimens. Effective on 

plastics & cotton 

sheets. 

Resultant 

Colour 

Blue - black 

COOMASSIE BLUE 



Bloodstained 

specimens. 

Navy blue 

AQUEOUS LEUCOCRYSTAL 

VIOLET 


blood. 

Bloodstained 

specimens. 

Purple 

HUNGARIAN RED 



Bloodstained 

specimens. 

Red 

CROWLES DOUBLE STAIN 



Bloodstained, nonporous 

items. 

Blue 

LEUCOMALACHITE GREEN 

Heme-reacting 

chemical reagent. 

Bloodstained 

specimens. 

Dark Green 

LUMINOL 


hematin. 

Presumptive test for 

blood. 

Luminescence - low 

intensity & short 

duration. 

View with FLS. 

GENTIAN VIOLET 

Reacts with epithelial 

skin cells and 

sebaceous 

components. 

Light-coloured adhesive 

tape 

Purple 

STICKY SIDE POWDER 

Physical process. 

Mixture fills in ridge 

impressions. 

Light-coloured adhesive 

tape 

Black 

TITANIUM DIOXIDE 

Chemical reaction 

Use on plastic, electrical 

& duct tape (both 

sides). 

White

SUBSTRATES AND SUGGESTED LATENT IMPRESSION ENHANCEMENT 

TECHNIQUES 

(O.P.C. F.I.O. TRAINING MANUAL) 

NOTE: The following list represents the techniques most likely to give satisfactory results. The 

number of variables involved in any examination makes it impossible to be specific. Each substrate 

or exhibit must be assessed on its own merits and the final selection of technique made by the 

technician at the scene. Examination of possible inherent fluorescence is recommended prior to 

other enhancement techniques. Consideration should also be given, of course, to creating the best 

contrast. 

The methods listed here are only to give you suggestions and as a place to start your consideration 

of which techniques to apply. 

Check with your own unit for advice as to which techniques are in local use. 

GLASS 

Clean 

Metallic powder such as aluminum or copper 

Greasy 

Granular powder – white is first choice but black and red can be used 

Dirty (e.g. mud splashed residential, factory or car windows) 

Look for take-away impressions, photograph before development process if possible. 

Granular powders will be more effective than metallic. 

METAL 

Highly Polished; Plated; Brushed finish; Galvanized. 

Cyanoacrylate fuming or camphor smoke 

PAINTED SURFACES 

Hard Enamel (e.g. automobiles and household appliances) 

Aluminum or copper metallic powder 

Granular powders 

Gloss and semi-gloss household paint 

Granular powders, especially black 

Flat paint 

Ninhydrin spray, iodine fuming

Note – Use ninhydrin at a crime scene only when you have fully considered the health hazards and 

potential for damage caused by staining. Not for use at minor scenes. 

PLASTICS 

The large number of ‘plastic’ materials makes a definitive list of appropriate development 

techniques impossible. Materials having a very similar outward appearance often have completely 

different powdering characteristics. The following list is a general guideline only. 

Hard plastics (e.g. cash register trays, video and audio tape cases) 

Cyanoacrylate fuming 

Magnetic or granular powder (use hair brush) 

Soft plastics (e.g. garbage bags) 


Magnetic or granular powder 

Vinyl (e.g. purses, automobile interiors) 


Magnetic powder 

Cellophane (e.g. cigarette packages) 


White granular powder, magnetic powder 

Foamed Plastics (e.g. coffee cup) 


Powder suspension, magnetic powders 

Melamine and Arborite (e.g. counter tops) 

Magnetic powder, granular powders 


PAPER AND CARDBOARD 

Bond Paper and cheques 

DFO, ninhydrin, physical developer 

Paper that has been or is still wet 

Physical developer 

Paper Money 

Ninhydrin followed by physical developer 

Kraft paper and boxes 

Ninhydrin followed by physical developer (ninhydrin may react adversely with the substrate, 

test a small section first)

Waxed cardboard (e.g. milk cartons, soft drink cups) 


Magnetic powders, granular powders, powder suspension, iodine fuming 

FURNITURE 

Waxed or Polished 

Granular powder, cyanoacrylate fuming 

Oiled 

Generally unproductive, if necessary try granular powder, cyanoacrylate fuming 

Varnished or painted 

Granular powders, cyanoacrylate fuming 

Unfinished wood 

Granular or magnetic powders on very smooth surfaces, iodine, ninhydrin spray 

LEATHER (E.G. PURSES, BRIEFCASES) 

Magnetic powder, powder suspension if wet, cyanoacrylate fuming 

HUMAN SKIN 

Iodine fuming with silver plate transfer 

Transfer to ‘Kromekote’ which is then dusted with conventional or magnetic powders 

Magnetic powder direct 

Laser fluorescence direct 

WET SURFACES 

While wet, treat with powder suspension or physical developer or 

Allow to dry and then treat with conventional methods i.e. powders and/or physical 

developer 

COLD SURFACES (i.e. BELOW FREEZING) 

Remove to warm area and allow to warm to room temperature 

Use conventional methods (powders, CA) as soon as condensation evaporates. Powder 

suspension may be effective 

Examination while frozen is unlikely to develop impressions 

HOT SURFACES (E.G. AUTOMOBILE IN SUMMER SUN)

Remove to shaded area, allow cooling. Usual powders, CA, powder suspension may be 

effective. 

MULT-COLOURED SURFACES 

Fluorescent powder applied under U.V. energy source, photograph by U.V. fluorescence. 

Cyanoacrylate and dye with Ardrox dye. Illuminate with U.V. and photograph the 

luminescence. 

DRIED-OUT IMPRESSIONS 

“Huffing” and powdering technique 

Powder suspension may be effective 

Freeze-thaw technique if object can be placed in a freezer.

Examining the Crime Scene (O.P.C. Training Manual) 

(Crime Scene Walkthrough and Crime Scene Photography) 

Introduction: 

One of the greatest pioneers in the use of scientific evidence was Edmund Locard (1877- 

1966). 

“Every contact leaves a trace.” His principle also implies that at the same time the subject 

will take away on his/her person, clothing, car, tools, weapons etc., traces of the scene or 

the victim. 

Contamination of the Scene: 

Contamination of the scene by persons who have entered the area subsequent to the 

offence creates a problem of determining which traces were left by the criminal and which 

were left by the complainant (or investigators, 1 st responders etc.) 

Record identification information of ALL individuals who may have entered the scene. 

May need to obtain necessary samples from these individuals for elimination purposes. 

Planning the Search: 

Obtain as much information as possible about the offence and the scene itself before you 

commence a search of physical evidence. 

Complete information will assist you to make informed decisions on what to look for, where 

to look and which methods to use in collection and preservation of evidence. It will also 

lessen the chances of inadvertently overlooking or destroying evidence. 

Keep in mind that some information provided may not be accurate. 

Photographing the Scene: 

Photographs are taken to record the conditions at the scene and the appearance and 

location of individual objects of evidence. 

When evidence is located overall locating views, medium range views and very close-up 

views are taken. 

The Search for Physical Evidence: 

Search of evidence begins after taking the overall, or general, scene photographs. 

Generally follow the sequence outlined below when conducting a search: 

o The Route to the Scene 

• This might also be referred to as ‘the path of entry’. 

• You may be able to determine the culprit’s approach or path to the point of 

entry. 

• Look for footwear impressions, fibres and items that may have been dropped 

– as quickly as possible to avoid accidental destruction or loss of evidence.

o The Point of Entry 

• It may be obvious if the scene is a secured area such as an automobile, office 

or residence. 

• Imagine that you are the culprit to determine what may have been touched. 

• Examine these areas first but also expand to adjacent areas. 

o The Object of Attack 

• The object of attack may determine the culprit’s path to more than one 

location once inside. 

• Look for footwear impressions before looking for other evidence. 

• Some identification units are making 30-50% of their total individualizations 

on footwear evidence. 

o Other Logical Objects or Areas 

• Use common sense to determine possible items touched. 

• Complainant / witnesses may have information to assist with pointing out 

items that are out-of-place. 

• Do not overlook washrooms – gloves may be removed in this area 

• Never under-estimate the importance of eliciting information from victims 

and witnesses. 

o The Path of Exit 

• May be different from Point of Entry 

• Culprits may become more careless in a rush to flee the crime scene. 

Vehicles: 

The following should be considered: 

o Follow a logical sequence in order to avoid missing any area. Develop a work habit. 

Start with the outside and work in. Nobody should enter the vehicle until the seats 

and floor have been carefully examined. The circumstances of the offence will 

dictate the actual procedure. 

o Examine the following areas for fingerprints – 

• Roof above doors, trunk lid, the hood, edges of doors and windows 

• Side view mirrors, rear view mirror (may need to remove) 

• Steering wheel 

• Armrests and door handles (including inside of area that is used to pull the 

door closed) 

• Dashboard and console 

• Ashtrays 

• Knobs or handles on the seat controls 

• Contents of glove compartment 

• Debris found on floor such as cigarette packages, gum wrappers etc. 

Handling Exhibits: 

Very important that no object bearing possible impressions should be touched by anyone 

before you have had an opportunity to examine it. 

If a latent impression is touched with anything at all, be it bare hand, glove, handkerchief or 

anything else, it will be damaged.

The only exception is paper exhibits – impressions on paper are not damaged by pressure 

but, paper should only be handled when wearing gloves to avoid additional impressions 

being added (creates more elimination work and may interfere with existing prints) 

Make sure exhibits are not damaged by environmental conditions e.g. heat and humitdity 

Caution Re: Damage to Property: 

Use common sense to avoid further damage to complainant’s property. 

Health Concerns: 

Avoid inhaling fingerprint powders and chemicals 

Read the MSDS on the products you use. 

Ontario Major Case Management 

Legislated January 1, 2005 – Ont.Reg 354/04 

Minimum Investigative Standards (OMCM Manual and Regulation) 

Defined Major Cases 

Defined functions and responsibilities for all members of the Investigative Team. 

Defined Organizational Structure with one person clearly in charge. 

The Forensic Identification Officer is responsible for the examination of the crime scene, as 

well as for the audit of all exhibits either in the possession of the Police or the Centre of 

Forensic Sciences. 

As a Major Case Manager have you structured into your plan how you will react to inclement 

weather conditions. 

Three continuity logs must be kept at a crime scene: 

o Crime Scene Log (entry and exit) 

o Exhibit Log (located, seized and removed) 

o Body / Victim Log (contact and movement) 

All items of potential evidentiary value shall be identified, catalogued, documented, seized 

and preserved… (Ontario Major Case Management Manual) 

Closing the Crime Scene – “Only the Major Case Manager in consultation with the Command 

Triangle, the Forensic Identification Officer and the Scene Investigator, shall have the 

authority to release the crime scene…”

Fluorescence Techniques and Chemical Development of Latent Prints 

Light is electromagnetic radiation, particularly radiation of a wavelength that is visible to the human 

eye (about 400–700 nm), or perhaps 380–750 nm. [1] In physics, the term light sometimes refers to 

electromagnetic radiation of any wavelength, whether visible or not. 

Three primary properties of light are: 

Intensity 

Frequency or wavelength 

Polarization 

Light's Place in the Electromagnetic Spectrum 

The electromagnetic spectrum is the complete range of electromagnetic waves on a continuous 

distribution from a very low range of frequencies and energy levels, with a correspondingly long 

wavelength, to a very high range of frequencies and energy levels, with a correspondingly short 

wavelength. Included on the electromagnetic spectrum are radio waves and microwaves; infrared, 

visible, and ultraviolet light; x rays, and gamma rays. Each of these occupies a definite place on the 

spectrum but the divisions between them are not firm: in keeping with the nature of a spectrum, 

one band simply "blurs" into another. 

Over the breadth of the electromagnetic spectrum, wavelengths get much shorter, and frequencies 

much greater. The low energy side of the visible spectrum is red, the light with the longest 

wavelength. Infrared light and microwaves, not visible to the human eye, are even lower in energy 

(and even longer in wavelength). The high energy or short wavelength side of the spectrum is 

blue/violet. Ultraviolet is even higher energy, while x-rays and gamma rays are higher still, with 

even shorter wavelengths. 

Between infrared and ultraviolet light is the region of visible light: the six colors that make up 

much of the world we know. Each has a specific range and frequency, and together they occupy an 

extremely narrow band of the electromagnetic spectrum - from 700 down to 400 nm in wavelength. 

To compare its frequency range to that of the entire spectrum, for instance, is the same as 

comparing 3.2 to 100 billion 

NOTE - The human eye can generally detect no more than 16 – 32 various shades of gray.

Very approximate correlations between wavelengths and colour: 

(1 nm = 1 nanometre = one-billionth of a metre; 1 mm = 1,000,000 nm) 

Luminescence - 

1. The emission of light that does not derive energy from the temperature of the emitting 

body, as in phosphorescence, fluorescence, and bioluminescence. Luminescence is caused 

by chemical, biochemical, or crystallographic changes, the motions of subatomic particles, or 

radiation-induced excitation of an atomic system. 

2. The light so emitted. 

Photoluminescence - 

A luminescence excited in a body by some form of electromagnetic radiation incident on the body. 

The term photoluminescence is generally limited to cases in which the incident radiation is in the 

ultraviolet, visible, or infrared regions of the electromagnetic spectrum. 

Photoluminescence may be either a fluorescence or a phosphorescence, or both. Energy can be 

stored in certain luminescent materials by subjecting them to light or some other exciting agent, 

and can be released by subsequent illumination of the material with light of certain wavelengths. 

This type of photoluminescence is called stimulated photoluminescence. See also Fluorescence; 

Luminescence; Phosphorescence. 

Chemoluminescence - 

Emission of light as a result of a chemical reaction. Different chemicals require illumination with 

light from different regions of the spectrum to excite fluorescence and the wavelength (colour) of 

the emitted light varies from one chemical to another. 

Fluorescence - 

400 nm = Violet (Higher energy) 

450 nm = Blue 

500 nm = Blue/Green 

550 nm = Green 

600 nm = Yellow/orange 

650, 700nm = Red (Lower energy) 

Fluorescence is the property that some chemicals possess of being able to absorb light of a specific 

colour and then convert some of the absorbed energy into light of a different colour of longer 

wavelength. The time delay between absorption and emission is only a fraction of a second (less 

than 10 seconds) so that when the illuminating light is removed the emission apparently stops. 

Typically, light in the ultraviolet, blue or green parts of the spectrum is used to excite fluorescence 

which may result in the emission of light in the yellow, orange, red or infrared parts of the 

spectrum. (Because some of the energy has been lost before emission takes place, the light emitted

- fluorescence or luminescence - is of a longer wavelength or lower energy than the light that 

excited the molecule in the first place. Eg. Blue light of a forensic light source excites yellow 

fluorescence of R6G .) If the excitation light is green, the observed fluorescence will be yellow or 

red or even infrared, but not blue. 

Most of the illuminating light is usually not absorbed but it is scattered or reflected from the surface 

being examined i.e. the fluorescence is very weak. Filters which transmit the fluorescence but not 

the illuminating light (excitation light) are therefore placed in front of the eye and camera to enable 

the fluorescence to be seen and recorded. 

At the crime scene, it is unknown beforehand what fluorescent items might be found. The most 

useful combination of light source and viewing filter is blue light and an orange filter, but other 

combinations can also be tried. 

This colour wheel can be used for the 

selection of a filter (i.e. goggles or 

photographic lens barrier) to improve 

contrast. Colours that are opposite on the 

wheel are complimentary and will darken 

the colour observed i.e. increase contrast 

while adjacent colours on the wheel will 

lighten the observed colour i.e. reduce the 

contrast. 

For example – Try orange goggles if 

excitation light is in the blue range (400- 

500nm). 

Processing Technique - Fluorescence 

Certain properties of perspiration, body oils and/or foreign substances contained in latent print 

residue fluoresce when exposed to a laser or alternate light source. A filter is used to block the 

incident light of the light source. No pre-treatment of the specimen is required; therefore, no 

alteration of the specimen occurs. 

Use on all surfaces 

Non-destructive to specimen and subsequent examinations 

Detects prints on surfaces not suitable for powders or chemicals 

Detects prints not developed by other techniques

Procedures for conducting an examination: 

Conduct an examination in a dark room 

Aim expanded beam of light at object 

View object through an orange barrier or other appropriate coloured filter 

Preserve latent prints by photography 

The ability to detect fingerprints by fluorescence is dependent on three principal factors: 

1. The illuminating wavelength (or Excitation filter) must be appropriate to provide maximum 

fluorescence contrast between the fingerprint and the background; i.e. the correct 

wavelengths must be available for the chemicals involved, and there must be no significant 

stray light at the wavelengths at which the fluorescence is being viewed. 

2. Viewing or Barrier Filters include filters for goggles*, viewing housings and cameras (which 

must be selected for the chosen excitation filter before allowing light to be emitted from the 

forensic light source). The viewing filter must be suitable for protecting the eyes against the 

incident radiation, transmit the fluorescence, and where appropriate, separate the 

background and fingerprint fluorescence. It will completely block the excitation light, while 

allowing as much of the fluorescent emission through as possible. 

3. The system must produce an intensity of illumination at the surface high enough to produce 

sufficient fluorescence to be effectively observed and photographed. 

TYPES OF FLUORESCENCE EXAMINATION: 

Fluorescence examination may be used in two principal ways: 

As part of an initial examination procedure after a visual examination with white light; and 

As an enhancement technique after the application of certain development techniques. 

Initial Fluorescence Examination: 

With a laser or forensic light source, an initial examination of an exhibit can be carried 

out to look for inherent fingerprint fluorescence. 

It is frequently unsuccessful 

In some cases fingerprints appear darker than the surrounding surface. Generally this 

occurs when the fingerprint is contaminated with a material, such as blood, which 

absorbs the incident radiation and when the background is a material which fluoresces 

under the wavelength being used. 

Generally the operator has no way of knowing what the fluorescent materials are, and 

therefore no indication of which combination of excitation wavelength and viewing filter 

is going to be most effective. 

Experience with different surfaces, types of scenes and excitation and emission 

wavelengths will provide better guidance in the future, if comprehensive records are 

kept of all examinations, successful or otherwise.

CHEMISTRY OF FLUORESCENCE TECHNIQUES (C.P.C. Notes) 

INHERENT FLUORESCENCE 

With a laser or forensic light source, an initial examination of an exhibit can be carried out to look 

for inherent fingerprint fluorescence. That is, in certain circumstances, notably when the fingers 

have been contaminated with a foreign substance, fingerprints will fluoresce without the need for 

special treatment. 

CYANOACRYLATE (CA) 

Non-porous surfaces may be treated with CA fumes to develop prints. The CA molecules attach 

to one another on the fingerprint deposit, producing long polymer chains along the ridges. The 

CA polymer that builds up on the latent can sometimes be recorded with conventional 

photographic techniques, but often dyeing with a fluorescent chemical is required. 

Dyes: 

Most of the dyes used for CA staining rely simply on preferential absorption of the dye 

on to the CA, rather than the background. 

Under the correct illumination, the CA polymer treated with dye will fluoresce, resulting 

in greatly improved contrast between the ridge and the background. The dye molecule 

absorbs excitation radiation from the light source, and re-emits light of a different colour 

or wavelength. 

When the exhibit is viewed through a filter that blocks reflected excitation light but 

passes the fluorescent wavelengths, the fingerprint will be seen with very little 

background interference. 

R6G and “Brilliant Yellow” 

Rhodamine 6G, a laser dye, and Maxilon brilliant yellow favine (aka Basic Yellow, Brilliant 

Yellow), a textile dye, are two stains that work well with laser or forensic light source 

illumination. The dye can be dissolved in alcohol or water, and used as a spray or in a tank 

for dipping. The action of the dye on the CA is physical absorption rather than a chemical 

reaction, so the recipe for making up a solution does not require an accurately-measured 

concentration of chemical. For R6G, a stock solution of approx. 1g/L in methanol can be 

mixed up, and a portion diluted by a factor of about 40 (for a final concentration of .025 g/L) 

when required for use. Brilliant Yellow can be made up as a solution of approximately 2 g/L 

in ethanol. Because of the greater dangers resulting from splashing and the creation of 

aerosols, spraying is not recommended when exhibits can be dipped. 

Ardrox 

Ardrox is a fluorescent penetrant used industrially to look for surface flaws. The liquid will 

seep into cracks in the item being examined, and will become visible when excited by 

ultraviolet (UV) light. Ardrox-treated prints can also be observed with laser or forensic light 

source illumination.

For use on CA-treated prints, the liquid is diluted by a factor of 100 or more with methanol 

or water. As with the R6G or BY dye, exhibits can be dipped or sprayed, with dipping being 

the recommended method. 

In the case of all three dyes mentioned above, excess stain can be rinsed off the exhibit with 

the pure solvent or a gentle stream of water. Since the dye is not chemically-bound, 

vigourous washing can actually remove all of the dye from the latent print as well. This can 

be used to advantage if, for example, the background has absorbed a significant amount of 

dye, since more aggressive washing can then be used to attempt to clear off more of the 

dye. Exhibits can always be re-treated, if washing has removed too much dye. Most 

workers seem to agree that a more dilute solution results in less background interference. 

Exhibits rinsed with alcohol will usually dry more quickly with fewer spots. 

1,8 Diazafluoren-9-One (DFO) 

An amino acid reagent for detection of fingerprints on paper and some other porous 

surfaces. 

Produces a coloured and fluorescent product on reaction with amino acids and some other 

components in fingerprints. 

Colour is weaker than ninhydrin, but the fluorescence is, however, so strong that the use of 

this reagent in conjunction with a fluorescence examination system will generally produce 

many more fingerprints than ninhydrin alone would produce. 

DFO is dissolved in a mixture of methanol and acetic acid, then diluted in a carrier solvent. 

Paper exhibits are dipped in the solution, then allowed to air dry. A second dip has been 

recommended. After the exhibit has dried, the DFO reaction can be accelerated with dry heat. 

If immediate results are not required, the preferred development technique is to allow the 

exhibit to stand at room temperature for a few days. 

DFO-treated prints will fluoresce when excited by blue or blue-green light from a forensic light 

source, with the use of a suitable filter required to observe the fluorescence. DFO fluorescence 

can also be excited by longer excitation wavelengths. Use of green excitation light and red 

viewing filters can be useful on surfaces that are themselves somewhat fluorescent. 

Ninhydrin 

There are two methods of using fluorescence to enhance ninhydrin developed fingerprints: 

o 1) Excite the fluorescence of the background to increase the contrast against the 

non-fluorescent ninhydrin fingerprint 

o 2) Produce a fluorescent derivative of Ruhemann’s purple by means of treatment 

with a heavy metal salt – zinc chloride is normally used and this is referred to as zinc 

toning.

Forensic Light Source (eg. Luma-Lite) 

A forensic light source operates by simply filtering the output of a regular incandescent source. The 

bulb is a high intensity white light source that emits light across the entire visible spectrum. It then 

filters (excitation wavelength filters placed in front of the light source) down the light into individual 

colour bands (wavelengths) that enhance the visualization of evidence by light interaction 

techniques including fluorescence (evidence glows), absorption (evidence darkens), and oblique 

lighting (small particle evidence revealed). In many cases the background surface will also glow 

under light source illumination. In these cases it is necessary to tune to a colour band of light that 

causes the print to glow and not the background. The quality and quantity of evidence revealed is 

proportional to the output power and the extent of colour tuneability of the light source. This 

ability is exclusive to a FLS. UV lights or Blue lights cannot offer this selectivity due to their limited 

number of colour bands and low power. 

Utilizing forensic light source techniques allows the latent print to be detected with much more 

sensitivity (10-100 times more) than the conventional method of black powder dusting and lifting. 

Lasers 

A laser is an extremely focused, extremely narrow, and extremely powerful beam of light. Actually, 

the term laser is an acronym, standing for Light Amplification by Simulated Emission of Radiation. 

The light is monochromatic (a single colour) because it depends on a specific difference between 

energy levels in the substance that is lasing.

Alternate Light Source Reference Chart 

BAND COLOUR GENERAL APPLICATION 

400 – 700 nm White Light General searching & oblique lighting 

350 nm Ultra Violet General searching (stains & fingerprints) 

415 nm Violet (blood filter) Blood prints, spatter, gunshot residue 

450 nm Blue General searching (semen, urea, fibres) 

470 nm Blue General searching (ninhydrin prints) 

490 nm Blue General searching (semen, urea, fibres) 

505 nm Blue/Green Superglue & ninhydrin treated prints 

530 nm Green DFO treated exhibits, background reduction 

555 nm Green/Orange DFO treated exhibits, background reduction 

590 nm Orange Ninhydrin treatments, background reduction 

620 nm Orange/Red Ninhydrin treatments, background reduction 

650 nm Red Ninhydrin treatments, background reduction 

IR Infra Red Altered documents, inks 

Goggles to Use for Eye Protection 

Filter Clear Yellow Orange Red 

UV 350 * * * * 

415 * * 

450 * 

470 * 

490 * 

505 * * 

530 * 

555 * 

590 * 

620 * 

650 * 

690 * 

WHITE * 

IR 

GOGGLES WILL NOT BLOCK IR

General Study Guide - Ontario Police College

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