Firearms & Toolmark Unit

The New Mexico Department of Public Safety Forensic Laboratory Forensic Firearms/Toolmark Unit is a highly trained unit with five forensic scientists. This Unit examines evidence related to firearms, firearm components, ammunition, ammunition components, tools, and toolmarks. Evidence in a typical case may include recovered rifles, pistols, shotguns, magazines, and a variety of fired and unfired cartridges. Bullets, bullet fragments, shot wads, shot cups, and other firearms related evidence are also received from law enforcement agencies throughout the state.

Evidence submitted in toolmark cases may include bolt cutters, screwdrivers, scissors, knives, pliers, wrenches, crowbars, hammers, saws, wire, sections of sheet metal, chains, safe deposit boxes, human bone or cartilage, plates, locks, doorknobs, bolts, and screens.

Toolmark Comparison

Forensic firearms identification involves the identification of bullets, cartridge cases, and/or other ammunition components as having been fired by or in a particular firearm to the exclusion of all others. Internal, external and terminal ballistic principles are used; however, firearms identification is often inappropriately referred to as the field of ballistics.

Forensic scientists in the Firearm/Toolmark Unit microscopically compare ammunition components to each other, as well as to a known standard, to determine whether an association exists between or among the items submitted as evidence and the items whose origins are known. Similarly, forensic toolmark identifications involve the identification of a toolmark as having been produced by a particular tool, to the exclusion of all others. Scientists compare the micro- and macroscopic features of toolmarked items with known and questioned tools that may have produced them.

Bullet Comparison

The Integrated Ballistics Identification System (IBIS) is a computerized database system whereby digital images of markings on bullets and cartridge cases recovered in criminal investigations and those test-fired from recovered weapons are compared with ones from other states in our region. Potential matches are then confirmed by a firearms/toolmark examiner, using existing micro- and macroscopic techniques. IBIS is an important investigative tool, due to its potential to identify weapons used in crimes and to link serial crimes committed with the same firearm.

The Firearms/Toolmark Unit also performs many other related examinations. The Unit restores obliterated serial numbers on numerous types of surfaces, performs muzzle to garment distance tests and performs fracture match comparisons. Ultimately, the forensic scientists in this unit testify as expert witnesses in courts of law, regarding the foundational principles as well as case specific findings and conclusions.

The Firearm/Toolmark Unit staff are available to provide technical assistance in the collection and preservation of firearm / toolmark evidence and can be reached at: