Police use a variety of techniques in their investigation of serious violent crimes, such as homicide, robbery, assault and sexual assault. This paper systematically reviews experimental and quasi-experimental research on the effectiveness of these investigative techniques. Meta-analysis was used to combine effect sizes across multiple studies examining the same technique, crime and outcome.
Eighteen studies on 10 broad categories of investigative techniques were identified, with the largest number of studies examining specialised investigative techniques for sexual assault and the collection or testing of DNA and other physical evidence. While there were some promising findings, findings were mixed and, in some areas, there is limited evidence on which to draw strong conclusions. Given the significant investment of police resources in the investigation of serious violent crime, the results highlight the need for more methodologically rigorous empirical research on both new and established investigative techniques available to law enforcement.