As of December 2005, the NIBIN program included 228 partner sites representing 182 agencies. At least one NIBIN site is located in each state with the exception of Kentucky. The sites are grouped into 12 geographic regions, each of which is linked to servers in one of ATF’s three national laboratories. Servers at the ATF laboratory in Ammendale, Maryland, are the central hub for NIBIN sites in the northeast and north central states; servers in Atlanta, Georgia, link the southeast United States and Puerto Rico; and Walnut Creek, California, is the focal point for NIBIN sites in Texas, the western United States, Alaska, Hawaii, and Guam. The geographic distribution of NIBIN sites and servers is illustrated in Figure 5-1.
The regional servers are central to the operation of NIBIN. They are not only the central data repository for the region—combining and archiving data from the distributed sites—but also the “correlation” servers for the region as well. That is, an exhibit entered into NIBIN in Idaho is uploaded to the Walnut Creek servers for comparison with other NIBIN exhibits; the correlation results are then sent back to Idaho for review. Batches of exhibits are transferred from the local sites to the regional servers at least once a day; the exhibits are compiled, comparison scores are generated, and results and images sent back to the local sites.
Each of the regional servers is divided into several partitions; these partitions are important because they define the range of automatic comparisons (versus those comparisons requested manually). For example, NIBIN region 1B covers central and southern California, and it is divided into three partitions (roughly, northern, central, and southern). The southern partition contains two NIBIN installations: the San Diego Police Department and the San Diego County Sheriff’s Department. Hence, an exhibit entered into NIBIN by the San Diego County Sheriff’s Department is automatically correlated against exhibits from both San Diego-area NIBIN sites (after uploading to Walnut Creek). However, searches against data from other sites—Los Angeles or Orange Counties, for example, or Yuma, Arizona—must be specially requested by a NIBIN operator. The Inspector General audit of NIBIN (U.S. Department of Justice, Office of Inspector General, 2005:110) notes:
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.