Firearms / Toolmarks

The role of the Firearm and Toolmark examiner is to examine evidence which otherwise would stand mute before the bar of justice. A fully qualified Firearm and Toolmark Examiner, based on his or her training, research, and acquired knowledge, stands prepared to give voice to this otherwise mute evidence.

The Arkansas State Crime Laboratory currently employs four Firearm and Toolmark Examiners and also one Operation Shutdown Management Project Analyst.

By using a comparison microscope, a Firearm and Toolmark Examiner is able to compare bullets (from victims and crime scenes) and cartridge cases (from crime scenes) side-by-side against those test fired in guns submitted by various law enforcement agencies. The examiner can determine whether or not a bullet or cartridge case was fired from the gun in question by comparing the fine lines and markings on the surface. The examiner also does caliber determination on bullets, function and safe operation tests on firearms to determine if they are safe to shoot or could accidentally discharge.

Also by using a comparison microscope, an examiner compares the markings left at crime scenes by tools such as bolt cutters, screwdrivers, pry bars, knives, etc. to test markings made by the examiner using tools submitted by various police agencies.

Another duty of the examiner is to restore obliterated serial numbers on firearms or other items. After preparing the surface, the examiner applies different chemical solutions to restore the numbers.

After the case is worked, an examiner will write a detailed report concerning scientific findings related to Firearm and Toolmark analysis. Then, upon request, the examiner will testify in criminal proceedings based upon these findings as an expert witness in the area of Forensic Firearm and Toolmark examinations.

The Operation Shutdown Management Project Analyst is responsible for test firing and entering bullets and cartridge cases from all guns that are believed to be involved in a crime into the National Integrated Ballistics Information Network (NIBIN). These are guns that do not need any other examination.

The NIBIN database contains images of cartridge cases and bullets recovered at crime scenes, as well as cartridge cases and bullets from test fires of recovered firearms. As new images are entered, the system searches the existing database for possible matches. When the NIBIN system discovers a likely match, a firearms examiner must conduct a microscopic examination of the actual bullets and/or cartridge cases to make an identification.