Trace Evidence Section:

Trace evidence is generally considered small, physical material, that may be transferred during a crime, including: hair, fibers, gunshot residue, glass, paint/polymers/tapes, and unknown material. The Trace Evidence Section identifies and compares this microscopic evidence. Any physical contact between individuals and/or crime scenes has the potential to result in a transfer of trace material. The laboratory may receive trace evidence collected from a scene or receive items to be processed for trace evidence. Trace evidence is frequently found at crimes scenes such as homicides, rapes, assaults, burglaries, and automobile accidents (hit-and-run).

The trace evidence section has the following types of instrumentation available:


Transmitted Light Microscope

Polarized Light Microscope (PLM)

Fluorescence Microscope

Comparison Microscope

Scanning Electron Microscope, equipped with Energy Dispersive Spectrometer (SEM-EDS)

Laser Induced Breakdown Spectroscopy (LIBS)

Laser Ablation Inductively Couple Plasma Mass Spectrometer (LA-ICP-MS)

Fourier Transform Infrared Spectrophotometer, Bench or Microscope (FTIR)

Raman Microscope


Glass Refractive Index Measurement System (GRIM)

Pyrolysis Gas Chromatograph Mass Spectrometer (Py-GC-MS)

Solubility Testing

Melting Point Evaluation

The Sacramento County District Attorney’s Office Laboratory of Forensic Services, also has an extensive reference collection of various types of trace materials to aid in examinations.