Forensic Services
Forensic Biology
The Forensic Biology Section is responsible for the detection, identification, and comparison of biological evidence. This section is staffed by a Supervising Criminalist, five Criminalists, and three Crime Laboratory Specialists. The Forensic Biology Section caseload consists primarily of sexual assault cases and homicides. Occasionally, a burglary, robbery, or assault case might involve biological evidence.
Biological evidence may be present as blood, semen, saliva, hairs, or other cellular material.
A Typical case begins with screening (Serology) for the presence of biological evidence. Simple chemical tests (Kastle-Meyer, acid phosphatase detection, amylase diffusion plates, and microscopy) will reveal the presence of a biological stain. Additional testing (ie. Microscopy, Immunological for species of origin) may also be performed to verify the case is a candidate for DNA analysis.
If probative evidence is present, it may is preserved for future analysis. At present, only violent crimes against a person qualify for DNA analysis. DNA analysis is commenced once the investigating officer submits standards (blood from the suspect and/or victim) and requests a DNA comparison. Cases lacking a suspect are initiated by an investigating officer's request that a DNA case be worked in the absence of a suspect.
The Utah Bureau of Forensic Services analyzes forensic samples using Short Tandem Repeat (STR) Polymerase Chain Reaction - (PCR) systems. This technology allows the simultaneous typing of several loci (areas of on the DNA molecule).
Casework samples are amplified using Applied Biosystems AmpFlSTR® Profiler-Plus® and COfiler® kits. The Amplified product is analyzed using the ABI 310 Capillary Electrophoresis system.
CODIS - The DNA Database
The DNA profiles from forensic specimens and convicted felons are submitted to a national database.
The Combined DNA Index System -- (CODIS) system is a program that is headed by the Federal Bureau of Investigation - (FBI). The objective of this database is to link serial crimes on a national level, much like the Automated Fingerprint Index System -- AFIS. This system has had tremendous successes by solving several high profile crimes that would otherwise not have been solved.