KNOXVILLE POLICE DEPARTMENT - City of Knoxville

The Forensic Unit is staffed by sworn and non-sworn police personnel and is comprised of 5 specialdetails: Crime Scene Processing, Fingerprint Identification, Firearms Identification, Photo Lab,and Polygraph. Through these specialties, the Unit provides services from bullet comparisons tocrime scene reconstruction. The Knoxville Police Department in partnership with area colleges anduniversities host forensic science student interns throughout the year. The Unit also hosts presentationsto area citizens groups, scouts and school groups.The Forensic Unit responded to over 5,295 calls for service in 2009, rangingfrom simple vandalism to homicide. The Unit is responsible for gathering evidencesuch as shoe impressions, chemically developed bloody handprints, andfingerprints from weapons used in crimes to aid in solving violent and othercrimes in the City of Knoxville. Composite sketches are used to identify suspects;presumptive testing of blood at crime scenes give investigators importantinformation in the early stages of a homicide investigation; ballistic comparisonsmatch firearms to bullets; and numerous latent fingerprints havebeen identified by our Latent Print Examiners. Polygraph examinations arealso routinely used to aid with developing investigative leads.The Crime Scene Detail provides in-depth field crime scene processing and forensic services thatinclude latent fingerprint collection, impression casting of footprints and tool marks; and the collection,processing, and preservation of evidence at crime scenes. Crime scenes may also be documentedwith photography, videotaping, field sketches and laser data plotting with the use of theDelta Sphere or Total Station instruments. The services provided by this detail support the officer,investigator and court prosecutors during prosecution.The Polygraph Detail conducts criminal and pre-employment polygraph tests, which are differentin nature and content. Criminal examinations are specific issue tests with the goal of finding deceptionin the suspect of a crime. Each examination consists of a pre-test interview, polygraph examination,and a post-test interview. The Detail assists investigators in identifying perpetrators and bringingcases to successful closure. In 2009, the Detail conducted 109 polygraph examinations.The Photography Detail develops and processes photographs for all City of Knoxville departments.These services include creating enlargements for court presentations, converting photographsto slides, and photographic services at special events throughout the City. In 2009 over13,355 photographs were processed.The Firearms Detail is participating in the Bureau of Alcohol, Tobacco, Firearms and ExplosivesNational Integrated Ballistic Information Network (NIBIN) program. The Detail is responsible for imagingfirearm evidence collected, and searching and comparing the evidence against a national database.Positive database search results are then confirmed with the use of a comparison microscope.In 2009, over 563 microscopic comparisons were performed resulting in 76 positive matches.The Fingerprint Detail uses the nationwide-computerized Automated Fingerprint IdentificationSystem (AFIS) to assist officers and investigators in matching fingerprints to unidentified suspectsand victims. The Detail searches for evidence left behind by suspects at every crime scene. Collectedlatent prints are then hand entered into AFIS. The Detail is responsible for matching the latent print2009 Annual Report 33