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Chemical Unknown Analysis

The analysis of chemical unknowns involves the examination of non-narcotic materials. This type of evidence can be encountered at a variety of crime scenes, including burglaries, homicides, vandalism, and assaults. Evidence may be in the form of a solid, liquid, mixture, or gas. Submissions may be for identification and/or comparison to a known sample.

Common materials encountered by the Chemical Testing Section include:

  • Pepper sprays and tear gas
  • Bank dyes
  • Acids, bases, and bleach

Other materials that have been analyzed include fire extinguisher residues, adulterated drinks, various organic liquids, and unknown white powders used in hoax devices or as threats. 

An example of a powerful pepper spray used in an assault and robbery, which eventually lead to a shooting. The chemical components of this spray were found both at the scene and on one of the suspect’s clothes.Bear Deterrent

Bottle Bomb


An expended chemical reaction bomb. Often intended as harmless pranks, some of the chemicals used in these devices can cause serious burns.  The pressure from the gas released can be sufficient to cause property damage and bodily harm. 



Dye Pack Pants


The inside of a pocket in a pair of sweatpants worn by a bank robbery suspect. The stains are from an exploding dye pack. A hole was also burned through the fabric when the pack went off.






The Chemical Testing Section examines solid materials that may have been used to start a fire such as road flares and household chemicals. 

A mini-Molotov cocktail