In some criminal cases involving firearms, there may be an open question as to whether a given person is in possession of a firearm or used such in a crime. These cases range from illegal possession of a firearm by a prohibited person (such as a felon) where there are multiple people near the firearm to linking it to a crime to murder cases. There are five key ways a prosecutor (or defense counsel) may link or challenge a gun to a person or crime.
The first is the oldest and most common technique—latent fingerprints. Latent fingerprints are those left on an object at the scene of a crime that may not be visible to the naked eye. With the right handling, an object may be “dusted” and these fingerprints removed and linked to anyone who has handled the firearm. Not all latent fingerprints recovered may conclusively link a potential defendant to a given firearm.
Second, with the advancement of DNA testing, genetic “fingerprinting” is possible. This is done by taking cheek swabs inside the mouth of a defendant and seeing if this matches DNA recovered on the firearm (and other weapons). In this case, it is critical that very specific protocols be followed to avoid contamination of the DNA samples. Failure at any step of this proceeding may make any DNA testing suspect.
Third, a given bullet case (expended and generally left on the ground at a crime scene) and or projectile (bullet recovered from a thing or person) may be matched to a given firearm by specific and unique damage to each caused in the course of shooting. To too is a very technical area of law and may subject to “junk science” if not completed using advanced tools, such as a microscope and other scientific testing that is unlikely to yield a false linkage between either and the firearm and the fired components.
Fourth, the firing of a firearm creates a unique chemical signature that may be found on the person or clothing of the person firing the firearm. This takes recovery and testing of these items before they are washed or stolen. This is less likely to of use to a defendant because it is likely he or she has left the scene and this evidence lost to time (bathing and washing of clothes). Nevertheless, in the right type of case this may be useful for a defendant and mounting a defense.
Finally, lost or stolen firearms may be traced to a defendant (or provide a defense) by checking the serial number with that maintained with the ATF. Firearms’ dealers have a legal duty to report missing firearms.1 Those outside of the industry may make a police report and report the lost or stolen firearm and serial number. Depending upon the situation, this may make the firearm easier to link to a defendant or provide a defense.
Firearms used in crimes and a potential defendants have a number of ways to challenge any gun alleged to be used by them in connection with a crime. This is a technical area and may require and expert to properly defend the case. This blog post was written by attorneys at Ciyou & Dixon, P.C. whose attorneys practice throughout the State; Bryan L. Ciyou consults of firearms issues around the United States.