Does forensic dna help to solve crime? The benefit of sophisticated answers to naive questions

Forensic science has played an increasingly important role in the investigation of crimes. We argue in this paper that, in addition to bench science, field experimentation involving forensic methods is critical to properly assess the relative utility of various methods of solving crimes. We illustrate this point by summarizing the findings from a recent Campbell Collaboration systematic review of field studies of the effectiveness of DNA testing. Our search identified five studies, including one randomized-controlled-trial of the value of DNA testing in burglary cases. The findings generally support the value of DNA testing for police investigations, particularly for high volume crimes such as burglary, although most of the empirical evidence is methodologically weak. Additional work is clearly needed, not only with respect to DNA testing but other forensic methods as well.