Fairfax County

Fairfax County Police Debut Gun Tracking Technology

Detectives in Fairfax County, Virginia, are using the technology to match guns and cartridge casings

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A computer technology that can match the unique marks a gun makes on cartridge casings is helping detectives in Fairfax County, Virginia, to track down people suspected of violent crimes more quickly.

Detectives took News4 into their crime lab to demonstrate how they used a gun found at the scene of a shooting to look for a lead in the case.

First, police fired the gun into a machine and recovered the cartridge casing.

"For this one cartridge case, this is what we're gonna enter," Fairfax County Police Detective Terry Leach said.

Leach then took the casing and loaded it into a computer system, which captured a high-definition 3D image of the casing.

Like a metallic fingerprint, every gun leaves unique marks on cartridge casings, and each round shot will have nearly identical markings.

Leach uploaded the cartridge image to a cloud database maintained by the ATF to see if the gun's casings had nearly identical markings to the casings recovered from other scenes.

Moving the images and lighting them from every angle, Leach found a match. The gun police recovered was connected to a known case, giving detectives a lead.

"Matching the gun to the shooting is a huge win for the investigation," Fairfax County Police Officer Joe Moore said.

Police say the technology is yielding significant results. Previously, casings were sent to the state crime lab and might not yield a lead for as long as a year.

Last summer, Gret Glyer was shot and killed while in bed with his wife inside their Fairfax home.

Detectives had cartridge casings from the bedroom and they had a suspect, Joshua Danehower, but police needed more evidence to charge Danehower.

Investigators followed Danehower to a local shooting range and collected his cartridge casings.

They used the technology to compare the casings from the crime scene and the shooting range, which found that they came from the same firearm, according to court records.

The analysis lead, in part, to Danehower's murder indictment. Danehower pleaded not guilty and is awaiting trial.

"We've been up and running for about a year. We've made hundreds of entries and gotten dozens of correlations back," Moore said.

Fairfax County is the only local department in the region with the system.

The technology doesn't track legal gun owners and police said casings are only entered in the system when they are recovered from violent crime scenes.

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