FORENSIC SCIENCES: CRIMINALISTICS - Bio Medical Forensics

The hawksbill sea turtle (Eretrmochelys imbricata) is one of seven
sea turtle species, all of which are protected by international law. One of
the distinguishing characteristics of the hawksbill sea turtle is its carapace
(shell), which is covered with keratinous overlapping plates called scutes.
These scutes are the source of tortoiseshell products, which are widely
though illegally available in countries around the world. Scutes are
molded and pasted together with water and heat into products such as
glasses, jewelry, and small boxes. The tortoiseshell trade is one of the
main causes of the hawksbill sea turtle endangered status. Unfortunately,
given the global range of hawksbills, it has been impossible to discern the
origin of illegally sold tortoiseshell items; such items could originate
locally or be shipped from distant locations. This makes conservation
efforts difficult or impossible, as illegal harvesting and trafficking routes
are not defined.
In the research presented, DNA was first extracted from the shell of
hawksbill museum specimens to test the feasibility of DNA recovery.
Species specific PCR primers were designed to amplify approximately
440 base pairs of the mitochondrial control region. The amplicons were
then sequenced using the same primer set, after which mtDNA sequences
were analyzed and haplotypes determined. Next, tortoiseshell items were
obtained from the U.S. Fish and Wildlife Service from stockpiles
confiscated from individuals entering the United States. mtDNA was
again purified, amplified, sequenced, and haplotypes determined.
Importantly, haplotypes corresponding to the geographic origins of
hawksbills are available as a result of population structure studies of this
species, which show nesting site uniqueness and fidelity. Such
uniqueness allows for insight into the geographic origin of poached
turtles, which was then determined for all illegal hawksbill items.
The extraction of mtDNA from tortoiseshell items has never before
been accomplished, thus it represents a unique and powerful new tool for
law enforcement and endangered species conservation. Methods
developed and data collected during this research, combined with the
existing database of sea turtle haplotypes, for the first time allows precise
targeting of efforts to stem the illegal taking of these endangered and
internationally protected turtles.
Mitochondrial DNA, Wildlife forensics, Tortoiseshell
A32 Probative Value of Male DNA on Underwear
Collected From Female Children With Adult
Male Caretakers
Sarah Geering, BS*, Stephanie King, PhD, Shelly Steadman, MS, Steven
Hoofer, PhD, and Robert C. Hansen, MS, Sedgwick County Regional
Forensic Science Center, 1109 North Minneapolis, Wichita, KS 67214
After attending this presentation, attendees will appreciate the results
of autosomal and Y-STR analysis of the interior and exterior aspects of
female children’s underwear under normal caretaking situations.
This presentation will impact the forensic science community by
examining the probative value of the presence of male DNA from a
primary caregiver on children’s underwear in the absence of semen.
Y-STR technology in public forensic biology laboratories has
allowed for male-specific testing on an increased number of evidentiary
items across the United States. Cases submitted for biological
examination to the Sedgwick County Regional Forensic Science Center
(Wichita, Kansas) by the Exploited and Missing Children’s Unit often are
candidates for Y-STR typing primarily because the nature of the assault
involves very low quantities of male DNA. As child crimes typically are
not reported immediately to authorities, secondary items such as clothing
and bedding often are submitted for examination in lieu of sexual assault
examination kits.
In these situations, when the alleged male suspect cohabitates with
the complainant, the probative value of secondary items arguably
diminishes because it can be reasonable to expect DNA from the male
suspect to be present on those items. This can be true for secondary items
that are shared (e.g., bed linens) or unshared (e.g., clothing) between the
victim and male suspect. Even when examining underwear from the
victim – a typical unshared item with high probative value – it can be
reasonable to expect DNA from the male suspect to be present due to
DNA transfer during caretaking activities. These activities include
folding laundry, commingling of garments prior to or after washing,
batched washing and drying of clothing, and general assistance with
lavatory use or routine dressing.
The purpose of the present study was to investigate the probative
value of male DNA on children’s underwear in the absence of semen by
examining the quantity and quality of male DNA present on underwear
from female children that were exposed to normal caretaking activities or
commingled laundry situations, or both. Samples were collected from
exterior (tapings) and interior (swabbings) aspects of ten pairs of worn
underwear from three female children (ages two to six).
Human DNA was detected on the exterior and interior aspects of all
ten pairs of underwear, and autosomal STR testing yielded major
contributor profiles that were consistent with each underwear donor.
Minor contributions to the autosomal STR profiles were detected in five
exterior tapings. Foreign contributions in three of these five samples
were minimal, whereas the other two produced foreign contributions that
were substantial. Notably, Amelogenin Y was observed as a minor allele
in just one exterior sample. For the interior swabbings, only one
autosomal allele foreign to the underwear donor was observed in one
sample.
Male DNA was detected on the exterior aspects of the underwear in
all ten cases, whereas it was detected on the interior crotch linings in just
four of the ten cases. Y-STR profiles were obtained from all exterior
samples, three of which were single source profiles, and seven were
mixtures of two or more individuals. For nine of the ten exterior samples,
the father could not be excluded as a contributor to the profile. Y-STR
profiles were obtained from just eight of the interior samples, four of
which were single source profiles, and four were mixtures of two or more
individuals. For seven of the interior samples, the father could not be
excluded as a contributor to the profile.
Results of this preliminary study confirm that it can be reasonable to
expect male DNA to be present on unshared clothing (underwear) from
female children due to DNA transfer during caretaking activities. This
can be true even for the interior crotch aspect of the underwear and/or
DNA samples with undetectable quantities of male DNA. In conclusion,
in the absence of confirmed seminal components, the probative value
and/or relevance of male contributors on secondary items should be
considered carefully prior to subjecting such items to additional timely
and costly Y-STR testing.
Y-STR, Clothing, Trace DNA
A33 Casework ICPMS/IRMS Examples in
the Netherlands
Martin R. van Breukelen, PhD, and Andrew van Es, PhD, Netherlands
Forensic Institute, Laan van Ypenburg 6, The Hague, 2497GB,
NETHERLANDS; Gerard J.Q. van der Peijl, PhD*, Netherlands
Forensic Institute of the Netherlands Ministry of Justice, PO Box 24044,
The Hague, 2490 AA, NETHERLANDS; and Wim Wiarda, PhD,
Netherlands Forensic Institute, Laan van Ypenburg 6, The Hague, 2497
GB, NETHERLANDS
After attending this presentation, attendees will understand the
advantages of the transparant and interactive nature of reporting of
forensic ICPMS and IRMS results to both police as well as court
authorities in the Netherlands.
The presentation will impact the forensic science community by
providing insight into the use of forensic (LA-)ICPMS/IRMS results
17 * Presenting Author