Abstract
Highlights from the major empirical studies on the criminal investigation process, and the role played by physical evidence in that process, are reviewed in light of findings from empirical studies on the effects of forensic analyses on criminal cases. The review reveals that most criminal cases do not involve the use of any physical evidence and that such evidence, even when available, is seldom seen by police detectives as having any intrinsic value. Detectives use physical evidence primarily to strengthen their position vis à vis the suspect's for the purpose of clearing cases by confession. Nevertheless, some research shows that physical evidence improves clearances and convictions in burglary and robbery cases, which traditionally have low case resolution rates. Enhancement of the use and value of physical evidence to investigators, crime laboratory specialists, and others involved in criminal processing requires improved communication and collaborative efforts. Training of police and prosecutors should be particularly emphasized because they have the most to say about whether and how physical evidence is used in the investigation of criminal cases.
