Evidence retention policies in U.S. law enforcement agencies: Implications for unsolved cases and post-conviction DNA testing

Abstract

The use of forensic evidence in the criminal justice system has grown appreciably in the United States. Yet policies that dictate how state and local agencies maintain and store forensic evidence have not kept pace. This study examined the prevalence of evidence retention policies, as well as storage locations and tracking systems, in a nationally representative sample of state and local law enforcement agencies. Less than half of U.S. police departments have a policy for preserving biological evidence from convicted offenders. Among agencies having a policy, the responsibility for retaining evidence was most commonly placed with the investigating law enforcement agency. Implications of these findings and policy directions are discussed.