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Expert Systems Help Labs Process DNA Samples

NCJ Number
National Institute of Justice Journal Issue: 260 Dated: July 2008 Pages: 16-19
Date Published
July 2008
4 pages
Publication Series

This article reviews the National Institute of Justice's (NIJ's) evaluation of new software programs called "expert systems," which claim to help reduce the backlog of convicted offender DNA samples by shortening the time required to analyze a DNA sample.


The evaluation found that the three expert systems evaluated for single-source samples would help reduce the backlog of DNA samples for convicted offenders. Each system can rapidly and accurately conduct routine reviews of DNA samples without "flags" and can significantly reduce the time spent in the human review of DNA profiles. When using one of these expert systems, only one analyst is needed to accept the good-quality samples (two analysts are required without an expert system), thereby reducing labor hours by half. The systems, however, cannot fully replace a human expert or DNA analyst. The systems can only be used as tools in evaluating single-source DNA samples and to alert the DNA analyst when results do not meet defined rules, or there is a possible alternate judgment. The final decision in cases where results raise "flags" must remain in the hands of the trained DNA analyst. The expert systems evaluated were the GeneMapper ID Software v.3.2, FSS-i (exponent 3TM) software, and TruAllele System 2. All of these systems are publicly available for purchase, meet technical specifications outlined in the forensic standards, and can be used by people unfamiliar with computer code. Expert systems are a subset of artificial intelligence. They store knowledge on how to respond to a particular result and, when a challenge is presented, use the stored knowledge in the program to respond with an explanation. The system, however, cannot completely replace a human expert, because it contains only rules to solve most commonly encountered problems. 5 notes

Date Published: July 1, 2008