Once the evidence is collected and submitted to the crime laboratory, the firearms examiner can take digital images of the markings made on spent ammunition or from test firing the gun and enter them into a national database called NIBIN, the National Integrated Ballistics Information Network.
NIBIN was created in 1999 and is administered by the Bureau of Alcohol, Tobacco, Firearms and Explosives. It's a database that stores images of the breechface impressions found on the primers of fired cartridge cases. NIBIN also stores images of the scanned circumference of fired bullets.
What makes this database so useful is that when an image is entered it is automatically compared against other images in the database. Possible matches are then visually confirmed by technicians to determine whether each is a valid match or not. NIBIN allows agencies to link crimes that otherwise would potentially never be linked to one another.
According to an April 2009 factsheet found on the NIBIN Website, the NIBIN database has more than 1.5 million acquisitions and there have been more than 28,000 hits. The New York City Police Department leads the way with more than 2,100 hits alone. No doubt many more have occurred since then.
Hits, or matches, don't necessarily solve crimes or put criminals behind bars, but they certainly can. Dozens of success stories appear on www.nibin.gov:
In September 2005, the Charlotte Mecklenburg (N.C.) Police Department responded to four shootings, including a homicide where gunfire from outside an apartment struck the occupant and an armed robbery where a newspaper deliveryman was carjacked and shot. Using NIBIN, Charlotte Mecklenburg PD was able to link all of the shootings.
In October 2005, officers recovered the stolen vehicle and, using DNA, were later able to identify a suspect. In January 2006, detectives executed a search warrant at the suspect's residence, recovered a 9mm pistol, and arrested the suspect. Ballistics examination results matched the pistol to all four shootings.
In October 2007, following admissions related to the homicide and armed carjacking, the suspect pleaded guilty to second-degree murder and was sentenced to 20 years imprisonment. In January 2008, following arrest and conviction, the second suspect from the armed carjacking was sentenced to 11 years in prison.
In 2008 the Denver (Colo.) Police Department used NIBIN to link evidence recovered at an aggravated assault to an arrest of a gang member discharging a firearm.
Officers from the Aurora (Colo.) Police Department responded to a report of a drive-by shooting. When the officers arrived, they discovered that an unknown suspect had fired numerous rounds at the occupants of a residence and a vehicle in the driveway. The officers were able to locate the suspect vehicle and the four suspects inside. No firearm was recovered, but further investigation led officers to believe that the firearm was hidden at a friend's apartment. Eleven shell casings were recovered at the scene and submitted for entry into NIBIN.
Several months later, Denver police officers arrested a suspect for discharging a firearm. The firearm was test fired, entered into the NIBIN system in Denver, and found to match the ballistic evidence recovered during the aggravated assault that occurred in Aurora.
These success stories show the value in firearms examinations and the NIBIN database. Many agencies, including the Denver Police Department and the Los Angeles Police Department, mandate that every applicable case be entered into NIBIN and every recovered gun go through the NIBIN database. Both of these agencies have had exceptional results in linking and solving crimes.
Of course, the database is only as good as the data entry. If law enforcement agencies aren't submitting cases for entry, then the database won't be as effective as it should be. More submissions mean more hits. More hits mean more arrests. More arrests mean more convictions... Well, you get the idea.
David Spraggs is a major crimes detective and certified bomb tech for the Boulder (Colo.) Police Department. He is a member of the POLICE Advisory Board and a frequent contributor.