The Bureau of Alcohol, Tobacco, Firearms and Explosivesí
National Integrated Ballistic Information Network Program
Audit Report 05-30
Office of the Inspector General
Collecting and Entering Evidence
Evidence can be submitted for entry into NIBIN by either a NIBIN partner agency or from a participating law enforcement agency through a given partner agency. The ATF wants all crime-related bullets and cartridge casings collected at crime scenes, and all bullets and cartridge casings from test-fired firearms collected at crime scenes to be entered into NIBIN. The exceptions are evidence from .22 caliber firearms, firearms greater than .50 caliber, and shotguns, because the IBIS equipment is not capable of analyzing evidence from these types of firearms. During the audit, we determined the policies and procedures for the collection and entry of evidence into NIBIN varied among partner agencies. Therefore, the collecting and entering process described below is based on the protocol for ATF Laboratories, which is similar to the process used by the NIBIN partner agencies.
The types of cases that should be entered into NIBIN are those crimes that could be identified as “serial” in nature, such as homicides, attempted homicides, gang-type shootings, drug-related shootings, drive-by shootings, officer-involved shootings, robberies, and concealed-weapons offenses.
The process of entering firearms evidence into NIBIN is referred to as acquiring images. After the images are acquired, the next process involves comparing the images to identify potential matches and is called reviewing correlation images. The final process is examining the potential matches to identify hits and is called viewing results.
Comparing Evidence to Identify Potential Matches
After the firearms evidence is entered into NIBIN, the system can perform searches on a local, regional, or national basis to identify potential matches. In November 2003, the system was enhanced to track and compare ballistic images associated with crime firearms nationwide. Prior to the enhancement, the system could only track and compare images locally and regionally.
A local search is automatically performed by the system. Each time a correlation is requested, the system automatically searches within the partition location of the regional server that the partner’s IBIS equipment has been configured to search against.
Although regional and national searches can be performed, they must be manually selected. To perform a regional search, the requestor must designate where to search from a map of the NIBIN regions. The requestor is then presented with a list of all the partner agencies in that region, and can either search against all the partner agencies shown or de-select those partner agencies that the requestor does not want included in the search. To perform a national search, the requestor must repeat the regional search for each NIBIN region, as the system will not search all regions at once.
None of the searches result in a positive match of bullets or cartridge casings fired from the same weapon. Instead, the system produces high-confidence candidates that are similar. The IBIS equipment ranks a list of images based on their correlation results. If the images are similar, they likely represent images of ammunition components fired from the same firearm. After the system identifies the high-confidence candidates, the top matches must be reviewed by a firearms examiner to confirm whether an actual match has been identified.
Examining the Potential Matches to Identify Hits
To confirm the potential matches as a hit, the firearms examiner obtains the original evidence and compare the high-confidence candidates to the physical evidence. If the high-confidence candidates selected match the actual evidence, a hit is identified and marked in the system by the firearms technician. Once confirmed, the hit must be recorded in NIBIN for reference purposes. Once the hit is recorded, the reference case, and the image within the case file are displayed in red. If a hit occurs between two sites, the information is not transferred to the other site by the system. Rather, the other site must be notified to create the hit in its own database.
Other NIBIN linkages derived by investigative lead, hunches, or previously identified laboratory examinations are termed “warm hits” and should not be counted as hits. When there is an interagency hit, the agency initiating and confirming the microscopic comparison will be credited for the hit. For example, if “Agency A” discovers a high confidence candidate from “Agency B’s” evidence, “Agency A” requests the physical evidence for review and confirms whether the high-confidence candidate is an actual hit. “Agency A” is credited for the hit because it was initiated by “Agency A.” However, if “Agency A” determines a high-confidence candidate had previously been discovered as a hit or had been identified as a hit from previous investigations or leads, the high-confidence candidate is not marked in the system as a hit. When an interagency hit is confirmed, each involved agency should mark the hit in IBIS. Further, only the agency initiating and confirming the comparison should include the hit in its statistics reported to ATF’s NIBIN contractor. The NIBIN contractor reports the hit information to the NIBIN field coordinators, who report the information to NIBIN headquarters through an electronic reporting system known as the NIBIN case system.40