Alamance County sheriff Terry Johnson and Rockingham County sheriff Sam Page on Thursday heralded the work of a mobile lab of the Bureau of Alcohol, Tobacco, Firearms and Explosives in helping to solve local gun crimes.
This week, the lab has been concentrating on testing weapons recovered in Alamance County crimes, test firing them, retrieving the shell casings, and then studying and comparing the unique markings that result with a national database to determine if the same weapon has been used in any other crime.
Jason Walsh, resident special agent in charge of ATF in Greensboro, says each shell casing ejected after firing provides data as “unique as a fingerprint” on which gun fired a particular bullet, based on the shell casings recovered at a crime scene.
In an interview with The Alamance News, Walsh estimated that about 30 to 40 percent of the 600 or so weapons tested for Alamance County crimes this week came back with some lead for investigators to follow up on.
“Every gun is different,” Walsh emphasized, stressing that the unique markings produced when firing a gun allow the images to be examined and compared with other images. He said the accuracy level is more than 99.6 percent.
To demonstrate the process, agents from ATF fired two shots in a trailer behind the National Integrated Ballistic Information Network (NIBIN) van parked at the sheriff’s office this week from each gun that has been recovered at a local crime site.
Images of the resulting striations on each shell casing are then sent digitally to ATF’s NIBIN National Correlation and Training Center (NNCTC) in Huntsville, Alabama. The two samples are then analyzed and agents report back to the reporting law enforcement agency on what, if any, matches were found with the data base.
Using Huntsville can report back within 24 to 48 hours, allowing local deputies to follow up when a match is found.
During a press conference before the ATF demonstration to local news media, Sheriff Terry Johnson outlined several recent examples in which ATF agents found a correlation in the use of the same gun from one crime to another in Alamance County shootings.