NCPA - National Center for Policy Analysis

Using DNA Samples To Solve Crimes

February 19, 1998

Scientists and law enforcement personnel think the use of DNA matching to identify rapists and murderers is about to take off -- growing "geometrically," as one expert describes it.

In December, eight states began using F.B.I. software to match blood, semen or saliva left at the scene of a crime with a DNA profile in a database. The F.B.I. software allows states to pool their data online for the first time and thus identify criminals across state borders -- what investigators call a "cold hit."

Within minutes of linking up, a convicted sex offender in Illinois was identified as the perpetrator of a 1989 rape and attempted murder in Wisconsin.

  • Until now such match-ups have been sporadic -- totaling about 200 nationwide.
  • But matches are expected to speed up dramatically, now that the F.B.I. and state laboratories have finally set new technical standards for testing DNA strands.
  • Establishing a full-fledged national databank would be expensive, however -- with one expert estimating a cost of $500 million.
  • Then there are complex legal questions to be settled -- such as whether taking blood samples from prisoners constitutes an illegal search and seizure.

Advocates of DNA matching contend this tool will allow police to solve in one week cases which otherwise might have taken a year or more. Moreover, the risk of misidentification of offenders would be all but impossible. Already, 53 convicts have been exonerated after DNA testing was applied to the evidence in their cases.

Source: Carey Goldberg, "DNA Databanks Giving Police a Powerful Weapon, and Critics," New York Times, February 19, 1998


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