The 2007 National Institute of Justice survey of law enforcement forensic evidence processing.

The "Crime Report" made the following observation:

Only four in 10 law enforcement agencies have computerized tracking systems for forensic evidence, according to the results of a survey by the National Institute of Justice. The NIJ received responses from more than 2,000 state and local agencies which revealed, among other things, that in fourteen percent of unsolved homicides police had not submitted forensic evidence (including DNA, fingerprints and toolmarks) to the crime lab.

Links: http://www.ncjrs.gov/pdffiles1/nij/grants/228415.pdf
http://thecrimereport.org/2009/11/16/unanalyzed-forensic-evidence/