Firearms and Toolmarks

Firearms Sign

Welcome to the Firearm and Toolmark section of the Connecticut Department of Emergency Services and Public Protection, Division of Scientific Services. This section comprises of two examiners, four trainees and one NIBIN technician.  Evidence submitted consists of various types and calibers of firearms, firearm components, ammunition, ammunition components and items with toolmarks (unrelated to firearms) like evidence from forcible burglaries and property damage investigations.

Many people incorrectly refer to this discipline of forensic science as “BALLISTICS”.  Ballistics is the study of projectiles in motion. While knowledge in this area is important, what the Firearms section is actually doing is referred to as forensic firearm and toolmark identification.

By definition firearm and toolmark identification is, “an empirical comparative analysis that can determine if a striated or impressed mark was produced by a particular tool”.

Firearm identification is actually a sub discipline of tool mark identification. In the case of firearms, the firearm has many individual tools like the firing pin, ejector, extractor, chamber, barrel and magazine that all have the potential of leaving either an impressed or striated marks on the surface of components of ammunition during the firing or functioning of the firearm.  Comparison microscopes are used for examinations.

Comparison ScopeComparison Scope

comparison scope

The Firearms and Toolmark section has a reference collection with over 2,700 firearms.  They utilize a water tank and shooting range for test fires, operability and other examinations.


reference collection

Water Tank


Alcohol, Tobacco and Firearms

Association of Firearm and Toolmark Examiners