Firearms/Toolmarks

  

Firearms/Toolmarks

Firearms: 

                Function testing:  Submitted firearms are examined to determine whether the firearm is functioning as the manufacturer intended.  Firearms are examined for malfunctions in cycle of fire, safeties, trigger pull, or drop/impact firing when requested.

                Bullet/Cartridge Case/Shotshell Comparisons: When ammunition is fired from a firearm, markings from the inside of the firearm are imparted onto the surface of each ammunition component (bullet, cartridge case, or shotshell). These markings are unique to each firearm.  A microscopic comparison is done to look at the unique markings to link the bullet/cartridge case/shotshell to a specific firearm, if the firearm is submitted.

                Serial Number Restorations: When a serial number is obliterated from a firearm, etching chemicals are used to try and restore the number.

                Distance Determination: When a firearm is fired gunpowder is expelled from the muzzle of the firearm.   This gunpowder will create a pattern on the target object at limited distances.  Using this pattern and test shots from the questioned firearm, a bracketed distance of how far away the muzzle of the firearm was from object hit can be determined. This testing requires that the firearm believed to be used in the crime be submitted, as well as, the same type of ammunition believed to be used be submitted as well. 


Toolmarks: Tools will leave unique markings on the objects that it was used on.  Marks are usually found by tools that cutting, pry, or grip objects. Toolmarks found at a scene can be compared to a submitted tool to determine if that tool caused those marks.

Contact Information: 

General Crime Lab Number -  (307) 777-7607

Firearms/Toolmarks - (307) 777-6866