The TriggerPro Gun Swab Evaluation: Comparing the Use of a Touch DNA Collection Technique to Firearm Fingerprinting

Services: Program evaluation, Analytical studies

Research Areas: Criminal Justice, Public Safety

From July 2008 through August 2009, Indianapolis Metropolitan Police Department (IMPD) patrol officers in the East District were supplied with pre-packaged kits, known as TriggerPro ID, for use in collecting possible DNA samples from firearms encountered or confiscated during traffic stops or in response to other criminal incidents. TriggerPro gun swab kits are an example of “touch DNA” technology, which is an evidence gathering approach that attempts to collect viable DNA samples from small quantities of skin cells that remain after an individual has touched objects or places. The traditional method of gathering touch DNA evidence involves using a sterile swab moistened by distilled water.

The pilot project was designed to examine the effectiveness of swabbing firearms to collect DNA samples capable of connecting individuals to firearms. The evaluation of TriggerPro is based on a comparison of two forensic methods: fingerprinting firearms versus collecting touch DNA samples from firearms using TriggerPro gun swabs. Fingerprinting is the baseline against which the TriggerPro kits were compared. As the Southern District of Indiana Project Safe Neighborhoods local research partner, the Indiana University Center for Criminal Justice Research (CCJR), part of the IU Public Policy Institute and the IU School of Public and Environmental Affairs, was asked to conduct the TriggerPro evaluation. CCJR evaluation findings are summarized in this report.


Expert Team

Samuel Nunn
  • Samuel Nunn
  • Public Safety Research Director
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