Taking a Bullet’s Fingerprint?

By John F. Wilkinson

The National Integrated Ballistic Information Network (NIBIN) is a law-enforcement tool that essentially takes a bullet’s fingerprint. The NIBIN system was created to close a gap in investigative resources between the Federal Bureau of Investigation (FBI) and the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF). Prior to 1997 the FBI and the ATF each had its own system to examine recovered bullets and cartridge cases, with no practical way to share or compare the information collected by each agency. In 1997, Congress decided to create a unified ballistic information system for the entire country. The ATF’s Integrated Ballistic Identification System (IBIS) became the standard tool nationwide for gathering and recording ballistic information from recovered evidence (bullets, cartridge cases and firearms). The NIBIN program was created as a network over which this information could easily be shared regionally or even nationwide.

The Fingerprint

So, what does it mean to take a bullet’s fingerprint?
When a firearm is discharged, individual characteristics are imparted form the firearm onto the bullet or cartridge case. Individual characteristics are imperfections of the firearm, which typically occur during the manufacturing process, but also include possible rust, corrosion, or abuse by the owner of the firearm. These are enough characteristics, a firearms examiner will be able to tell you what firearm a bullet/cartridge case has been expelled from or if two or more bullets/cartridge cases were expelled for the same gun. The firearms examiner uses the IBIS system to correlate bullets or cartridge cases and, after comparison, can determine if a firearm has been used at numerous crime scenes. This information previously may have been overlooked.

In a typical case, when bullets or cartridge cases are recovered during an investigation, the bullets and cartridge cases are entered in to NIBIN system. To enter the evidence, a digitized image of the cartridge case is taken using IBIS and the resulting digital image is entered into the network. Once the image is entered, a computer search can be generated to correlate the recovered cartridge case image to images already entered into the existing database. The computer will locate any similar images for comparison. If the computer locates a similar image, a firearms examiner will compare the actual physical evidence to determine if the two cartridge cases were, in fact, fired from the same firearm. The computer match alone is never sufficient to conclude the bullets were fired form the same firearm. NIBIN’s procedural protocols require that a firearms examiner conduct a hands-on examination of the evidence to confirm the computer’s result.

Additionally, if a firearm is recovered, then it too can be entered into NIBIN. The weapon is test fired and then a digital image is taken of the cartridge case or bullet and entered into the computer. This image is compared to the existing database to see if there is a match.

Often, however, recovered evidence-whether cartridge cases, bullets or firearms-is not entered into the NIBIN system. Since NIBIN is very much like the Automated Fingerprinted Identification System (AFIS) or a recovered DNA database, in that is can make cold hit determinations, it is vital that firearms, bullets and cartridge cases are routinely entered into the system, just like taking fingerprints at booking or taking DNA sample from a convicted felon. Another problem is the logistical difficulty of doing actual physical comparisons of recovered evidence when the evidence is in a neighboring jurisdiction. To determine that two cartridge cases came from the same firearm, known as a “hit,” the firearms examiner must examine the actual shells side by side. Either a detective must physically take the evidence to the examiner or the examiner must collect the evidence for comparison.

Resources for the NIBIN Network

The NIBIN network is divided into 16 regions nationwide. Nearly 230 IBIS machines are deployed, maintained and supported by the ATF throughout those 16 regions. Every major metropolitan area in the country has a NIBIN system; rural areas can access the network through neighboring jurisdictions or the state’s crime lab. The ATF supports the program by providing the IBIS equipment, maintaining and updating the equipment and training local personnel to operate it. Localities must commit to allocate sufficient personnel to adequately enter the data.
A new innovation on the horizon for cities across the nation is the ability to use an electronic mapping system showing crime scene recoveries of firearm related evidence and gang activity. Every time a shooting incident occurs, information is entered into an electronic mapping system prior to entry in NIBIN. The location of the recovery can be entered along with the type of weapon and forensic information regarding the evidence. This information is subsequently projected onto a map of the locality or some portion thereof. Through graphics, the map can show where cartridge cases were recovered and show similar shootings, which have not been previously entered into the NIBIN system. Once a case is a confirmed link through a NIBIN hit, a case with no leads may be linked to an investigation with many leads or even a suspect in custody. This may prove invaluable in solving otherwise cold cases. One jurisdiction in California is testing this mapping technology, and it has proven helpful in numerous cases against gang members there.

The NIBIN program, in conjunction with the electronic mapping system currently being developed, is an innovation and effective tool to combat gun violence and gang related crime. But the program will only be successful and realize its true potential if recovered evidence is routinely entered into the system.

For more information, you may contact the NIBIN coordinator in your ATF Field Division.

Reprinted from “Swift and Certain,” vol. 3, no. 4. A publication of the Gun Violence Prosecution Program. National District Attorneys’ Association and American Prosecutors Research Institute.