“Smokeless powder” is the name given to modern gunpowder commonly used in firearms because it produces much less smoke than the black powder it replaced. When the National Research Council called for a “comprehensive national powder database” in 1998, it noted that such a database could enable investigators to better identify materials recovered at bombing scenes. The NRC report, “Black and Smokeless Powders: Technologies for Finding Bombs and the Bomb Makers,” also noted that existing powder databases were incomplete, making it difficult for investigators to match powders from a scene to database entries.
The incomplete nature of the databases, many of which were maintained by local crime labs, was the motivation of the NIJ-supported study by chemist Michael Sigman, of the University of Central Florida. Sigman, who is the director of the National Center for Forensic Science (NCFS), noted that this research project “directly addresses the need for an extensive and searchable database of smokeless powders that was identified in the 1998 NRC report.”
His goal was to expand the smokeless powder database to contain more than 800 records, including both legacy (primarily older powder sample records from the FBI) and newly purchased powder samples. As part of the project Sigman and his researchers provided a set of 100 smokeless powder samples to 42 ASCLD/LAB accredited laboratories. In addition to providing the physical samples, the researchers entered their analysis of each type of sample into the database. Finally, the project used the database to provide a statistical assessment of the value of a match between a database record and the physical and chemical properties of a sample.
When the work was completed, Sigman and his team had added 538 “historical records” of powders to the database, and an additional 100 smokeless powders currently on the market.
“These advances in data accessibility eliminate the need for individual databases in each laboratory and provide ASCLD/LAB accredited laboratories with smokeless powder references that they would not otherwise be able to attain,” the report said. And while the database has been expanded by the project, the researchers noted that the current database is only a “snapshot” because the manufacturers and types of powders on the market are continually changing.
“There is a need to continually update and expand the database,” they concluded, “especially given the widespread availability of smokeless powders in the U.S. and their frequent use in bombings.”
About This Article
The research described in this article was funded by NIJ award 2013-R2-CX-K008, awarded to the University of Central Florida’s National Center for Forensic Science. This article is based on the grantee report Smokeless Powder Reference Collection and SWGFEX Smokeless Powders Database Expansion (pdf, 71 pages) by Michael E. Sigma, Mary Williams, and Dana-Marie K. Dennis, National Center for Forensic Science, University of Central Florida.