The NIJ-funded Survey of was conducted to estimate the number of unsolved criminal cases containing forensic evidence that had not been submitted to crime laboratories for analysis. Of crimes received by U.S. law enforcement agencies during 2007, there were an estimated total of 33,696 unsolved rapes 73% of which had forensic evidence collected.  State and local law enforcement agencies reported an estimated 27,595 unsolved (18%) rapes that had not been submitted to a crime laboratory. The study explores explanations for evidence backlogs and implications for addressing challenges faced by communities.

The 2007 Survey of Law Enforcement Forensic Evidence Processing