Wednesday, November 11, 2009

'Unanalyzed evidence held by law enforcement agencies'

As questions continue to arise about the quality of modern forensic sciences, the National Institute of Justice in a new report (pdf) about "Unanalyzed evidence held by law enforcement agencies" raises questions about when and how forensics are used. According to the NIJ executive summary:

More than 2,000 state and local law enforcement agencies responded to a survey [1] to:

  1. Estimate the number of unsolved homicide, rape and property cases [2] nationwide that contain forensic evidence that has not been submitted to a crime laboratory for analysis.
  2. Determine the existence of policies and procedures regarding the processing, submission to a lab and retention of forensic evidence.

The survey showed that agencies:

  • Had not submitted forensic evidence (including DNA, fingerprints, firearms and toolmarks) to a crime lab in:
    • Fourteen percent of open, unsolved homicides.
    • Eighteen percent of open, unsolved rapes.
    • Twenty-three percent of open, unsolved property crimes.
There are reasons why a law enforcement agency may not submit forensic evidence to a lab. The evidence may be considered not probative, charges may have been dropped or a guilty plea entered. However, the researchers who conducted the NIJ-funded survey also concluded that some law enforcement agencies may not fully understand the value of evidence in developing new investigative leads.

The survey also revealed that:

The survey did not determine:

  • How many of the open cases would be solved or yield investigative leads if evidence in them were to be sent to the lab.
  • The number of cases in which evidence was analyzed in the past, but which now, with more advanced technology, might be solved or yield investigative leads. Read more about the potential value of the evidence.
The survey found 93% of agencies have no cold case squad assigned to check DNA samples in old cases. They also found 38% of agencies have no written policies about retention of biological evidence even though 80% of surveyed agencies were the primary entity responsible for storing that evidence. Fifty seven percent of agencies had no computerized system for tracking evidence in their possession (pp 49-51 in the pdf).

This research implicates efforts by innocence projects to find cases where DNA evidence could exonerate defendants in older cases, as well as efforts by police cold case divisions to identify the guilty from long-ago crimes. In practice, often agencies don't retain evidence from old crimes or fail to test (and even fight testing) evidence in their possession. I'm glad to see the feds starting to take a more comprehensive look at the practical issues surrounding these important questions.

1 comment:

rocko's world said...

It shocks me that the percentage of open homicides and unsolved rapes would be that high just because advanced technology is unavailable. I know that the cost is high and departments might be small but upgrading the technology could be the small piece of upgrade needed to help track down criminals and lower crime.