The Physical Evidence Section handles a large variety of cases including, but not limited to, rapes, homicides, burglaries, motor vehicle hit-and-runs, property crimes, and arson.
This section has two units: Serology and Trace Evidence.
The Serology Unit utilizes visual and chemical tests to examine items of physical evidence for the presence of body fluids, such as blood and semen. Additionally, samples may be collected for touch (or transfer) DNA analysis. Tape lifts are collected to preserve hair and/or fiber evidence that may be of value. Body fluid stains and touch DNA samples of potential value to the investigation are forwarded to the Forensic DNA section for further testing (i.e., Blood is confirmed and swabbed from the blade of a knife. The handle is swabbed to collect possible skin cells from the individual that handled the knife).
Collection techniques used in the Serology Unit include, but are not limited to: swabbing, cutting, and tape-lifting.
Testing techniques used in the Serology Unit include: Visual examination, Alternate Light Source examination, Acid Phosphatase presumptive test for semen, Microscopic identification of sperm cells, Seratec® PSA Semiquant confirmatory test for semen, Phenolphthalein presumptive test for blood, Takayama confirmatory test for blood, and HemaTrace® confirmatory test for blood.
The Trace Evidence Unit analyzes primer gunshot residue from suspects, analyzes fire debris for accelerants, and performs hair screening for DNA testing suitability.
The instruments used for analysis are the stereomicroscope, SEM/EDS (Scanning Electron Microscope/Energy Dispersive Spectrometer), and GC-MS (Gas Chromatography-Mass Spectrometer).
Upon completion of their examination, the analysts will write reports on their findings. They will also appear in court for expert testimony.