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Firearm and Tool Mark Unit

Forensic Firearms Identification deals primarily with the examination and comparison of fired ammunition components with known firearms. Evidence collected from crime scenes is examined and microscopically compared with test samples collected from test fired firearms in the laboratory in order to determine whether a particular firearm was used in an incident/or determining how many different firearms were used. Firearms Examiners use a comparison microscope to analyze the unique striations, or markings, left behind on fired bullets and fired cartridge cases.

In addition to comparative examinations, the firearm and tool mark unit performs functionality determinations on firearms submitted in violent crime cases. The laboratory utilizes an indoor firing range which contains a water tank, cotton box and a remote firing stand used for test firing damaged or unsafe weapons. Known standards are collected from submitted firearms and can be later compared to fired bullets and fired cartridge cases collected at crime scenes.

Occasionally firearms are submitted with obliterated serial numbers. The Firearms unit performs serial number restorations using a series of acids possibly discovering that the firearm was stolen or even tracing the firearm back to its owner.

Additionally, the firearms unit is partnered with the Bureau of Alcohol, Tobacco, and Firearms (ATF) in the usage of the National Integrated Ballistic Information Network (NIBIN). Specialized equipment known as the Integrated Ballistics Identification System (IBIS) is used to digitally capture images of fired cartridge cases which are then uploaded into NIBIN database which performs a computer-based comparison of the image against previously entered cartridge cases in the database. The primary goal of the program is to link fired crime scene cartridge cases back to a firearm and to link previously unassociated cases.

woman looking through microscope   machine holding a bullet   woman working at a computer   man shooting a gun into a machine   handgun in a machine   boxes of bullets on shelf

Customer Notification

Information for Customers Requiring Firearm Analysis

The following methods are used for firearm analysis in forensic cases by the Firearm and Tool Mark Unit:

Analysis Category Methodologies
Ammunition Component Examinations Stereo and Comparison Microscopy
Mechanical Function Examinations Safety checks, visual mechanical inspection, test firing
Serial Number Restorations Physical and chemical restoration methods
NIBIN Use of the Brasstrax and Matchpoint ballistic identification systems

Note: The current ASCLD/LAB-International accreditation of CCRFSL does not include the Firearm and Tool Mark discipline; the laboratory is working towards getting the unit accredited and adding it to its scope of accreditation.


The Association of Firearm and Tool Mark Examiners (AFTE)

National Integrated Ballistic Information Network (NIBIN)

Bureau of Alcohol, Tobacco, Firearms, and Explosives

American Board of Criminalistics (ABC)

American Society of Crime Laboratory Directors, Laboratory Accreditation Board (ASCLD)

The American Academy of Forensic Sciences (AAFS)

The Midwestern Association of Forensic Scientists (MAFS)

Criminal Justice Information Service