This is guidance for defining a “hit” on the NIBIN system. Please refer to this guidance, when reporting hit statistics to the ATF NIBIN Coordinator in your field division.
Definition of a Hit
A hit is defined as the linkage of two different crime investigations by a user of the NIBIN technology, where previously there had been no known connection between the investigations.A hit is a linkage between cases, not individual pieces of evidence. Multiple bullets and/or casings may be entered as part of the same case record; in this event, each discovered linkage to an additional case constitutes a hit.
A hit must be confirmed by a Firearms Examiner examining the actual specimens under a microscope. Other NIBIN linkages derived by investigative leads, hunches, or previously identified laboratory examinations, are not “hits” according to this definition. Therefore, other linkages previously termed “warm hits” should not be counted as hits.When an interagency hit occurs, the agency initiating and confirming the microscopic comparison will be credited for the hit.
Marking Hits in the IBIS System
Hits meeting the definition above should be linked in the IBIS system using the procedures provided in instructional materials from FTI. Remember that if a link is confirmed between two cases, it is necessary to note this in each IBIS case record. Linkages derived by investigative leads, hunches, or previously identified laboratory examinations should only be noted in the comments section of the IBIS screen. These linkages are not to be designated as hits. When an interagency hit is confirmed, each involved site should mark the hit in IBIS, using procedures provided in instructional materials from FTI.
Statistical Reporting
For interagency hits, only the agency initiating and confirming the comparison should include the hit in its statistics reported to ATF NIBIN. Please note when using a Heritage system, the "DART" function for generating hit statistics may not yield entirely accurate results. "DART", a database report generator, replaced the "Crystal Report" and was installed on all IBIS systems during the 3.4.6 software upgrade. When using the IBIS-TRAX systems, the reporting function is integrated to the analysis station, MATCHPOINT+. Instructional guides for both systems are available to assist users. Proper marking of hits in the system is required to ensure accurate counts when running the report.