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Who Loaded the Gun? Recovering DNA From Bullet Casings

NCJ Number
Date Published
September 2016
8 pages
This report describes the work being done by several scientists working under funding from the U.S. Justice Department's National Institute of Justice (NIJ) to improve the recovery of DNA from spent cartridge casings.
Researchers are focusing on how best to recover DNA - swabbing, soaking, or lifting with tape - and within those methods, determining which techniques are most successful. University of Denver biologist Phillip Danielson believes researchers are on the threshold in improving the actual DNA profile (the data to be analyzed) and the type of statistical tools used to do the comparisons. He believes the statistics are becoming more powerful, and the DNA profiling methodologies are getting better. David Foran, the director of the Michigan State University Forensic Science Program, believes the threshold is achieving a success rate that is sufficiently high to make DNA recovery from cartridge casings worth the time and effort of forensic investigators. Foran's group has improved the DNA recovery success rate to about 26 percent, which refers to an overall average of a full DNA profile obtained from a series of samples. Foran believes this average makes the testing worthwhile, because that could provide a potentially fruitful lead in a case. Forensic scientists involved in such research are now turning to the use of Next Generation Sequencing (NGS) to increase sensitivity and collect more detailed information from DNA. Danielson indicates that with NGS, some instruments can take a single molecule of DNA and sequence that molecule. Currently, the accuracy is not sufficiently persuasive, but researchers are moving toward greater accuracy.

Date Published: September 1, 2016