PULLMAN, Washington- A new study finds that forensic DNA analysis is woefully underused by police investigators in the United States.
The study by researchers at Washington State University estimated that 250,000 unsolved rapes and homicides in the United States since 1982 - more than half of such crimes - have yet to be subjected to DNA testing.
"The effectiveness of forensic DNA has created a tremendous testing demand that is not met by the available supply," said Travis Pratt, a criminal justice professor at WSU.
The reasons for low usage include lack of money, trained personnel and other resources for performing the complicated tests. The researchers' survey also found that some law enforcement agencies were reluctant to take and store DNA evidence.
Pratt and his fellow researchers from WSU gathered numbers from 120 crime labs and about 3,400 law enforcement agencies in all 50 states, using a grant from the National Institute of Justice, a government research agency.
They found that some law enforcement agencies still are reluctant to use DNA testing because it is expensive and requires more training, researcher Michael J. Gaffney said.
"We heard from agencies that had never submitted a DNA sample for testing," Gaffney said.
The researchers found that most law enforcement agencies still view DNA evidence as supplemental evidence, more useful to prosecutors in obtaining a conviction than to investigators in identifying the perpetrator.
Many law enforcement agencies were still unaware of the existence of the national DNA database, the study found.
"Nearly one-fourth of all the surveyed law enforcement agencies reported that one of the primary reasons for not sending DNA to a crime laboratory was the lack of a suspect in the case," the study says. "The problem with that is that those are the very types of cases in which the current national DNA database of existing criminal offenders can be most useful."
The report is slated for publication in an upcoming issue of the journal Criminal Justice Policy Review.
The researchers concluded that federal, state and local governments should consider spending more on DNA testing, but did not estimate how much cash will be needed.
A February report by the Bureau of Justice Statistics estimated that 1,900 additional full-time lab workers at a cost of $70 million (euro57.9 million) would be needed across the country to reduce the backlog in forensic laboratories to 30 days for both DNA samples and other crime lab work, which includes fingerprint and fiber analysis and ballistics.
The federal government and states are working to reduce the backlog and are making some progress. Two years ago the Justice Department launched a five-year $1 billion initiative to clear the backlog.
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