NCJ Number
228342
Journal
Forensic Science International: Genetics Volume: 3 Issue: 4 Dated: September 2009 Pages: 242-250
Date Published
September 2009
Length
9 pages
Annotation
This study determined that results from the Plexor HY System proved that DNA recovery from cartridge cases and shotshell cases is sufficient for STR typing for some samples.
Abstract
When individuals handled the cartridges/shotshells for 30 seconds prior to firing, a greater STR typing success rate was found when using the AmpFlSTR MiniFiler kit with cartridge cases and shotshell cases compared to the PowerPlex 16 BIO System and Identifiler Amplification kits; however, when testing a sampling of individuals of unknown shedder status, handling shotshells only as necessary for firing, no significant difference was observed when comparing the total number of alleles obtained from the PowerPlex 16 BIO and Minifiler kits. An average of two to three alleles was observed per profile for these samples. Using the MiniFiler kit, a greater percentage of alleles was observed from the hull versus the head of the shotshell case. Additional work should be done to determine whether an analyst should swab both the head and the hull of shotshell cases. The data developed do not support PCR inhibitors being present in the majority of shotshell case samples, but the results suggest that poor STR amplification results in shotshell cases are more likely due to DNA damage, possible degradation, and/or low level DNA. Swabbing the firearms surface areas that come into contact with the cartridge during the firing process was not useful. Additional work that uses several different types of ammunition in mock casework scenarios could indicate the usefulness of analyzing these types of evidence for touch DNA. Detailed descriptions of materials and methods used in the study are provided. 4 tables, 8 figures, and 26 references