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- October 31, 1988LAWConvicted by Their Genes
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- A new forensic test is revolutionizing criminal prosecutions
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- Jurors at the trial of Victor Lopez were troubled by a major
- discrepancy. Lopez, charged with sexually assaulting three New
- York women, is a light-skinned Hispanic, yet each of the women
- had told police that her assailant was black. Was he, as his
- attorney insisted, a victim of mistaken identity? No,
- concluded a jury in Queens, N.Y., last week; it found Lopez
- guilty of all three attacks.
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- Billy Lewis Glover Jr. had been tried twice for rape, but both
- Dallas proceedings had ended in mistrials. Earlier this month
- a third jury took just 22 min. to return the verdict -- guilty.
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- The pivotal evidence was the same in both cases: results from
- a new forensic test, known as DNA, or genetic,
- "fingerprinting," which can specifically match a suspect to
- genetic material in blood, hair or semen left at the scene of
- a crime. Hailed as the single greatest forensic breakthrough
- since the advent of fingerprinting at the turn of the century,
- the technique is being put to use with growing frequency in the
- nation's courtrooms. Orlando prosecutors scored the first
- conviction in the U.S. based on DNA typing just last November
- in a rape trial; since then it has figured prominently in more
- that 150 cases in eleven states.
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- Advocates claim the test will revolutionize the investigation
- of violent crimes, from rapes and homicides to armed robberies.
- It also promises to resole questions of kinship, a matter of
- import in child-support and immigration disputes, and will
- provide a reliable new means of identifying human remains.
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- In more than 1 million criminal incidents each year, suspects
- are not even arrested because evidence is too weak. "With DNA
- printing," boasts Robert Shaler of Lifecodes in Valhalla, N.Y.,
- one of three U.S. companies that offer the analysis, "police
- will now be able to say with certainty, "That's the guy,"
- instead of "That could be the guy."
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- Older biochemical tools, which have progressed from simple
- blood typing to analyzing specific enzymes and proteins, are
- crude by comparison. With the best combination of such methods,
- the chance of making a matching error is one of 1,000. DNA,
- however, is unique for each individual, and a matchup between
- a crime- scene sample and material obtained from the accused
- (usually in a blood sample) is virtually unassailable, say
- experts. Declares John Huss of Cellmark Diagnostics in
- Germantown, Md., another DNA-testing firm" "Except for
- identical twins, one in 4 trillion or 5 trillion people might
- share the same genetic fingerprint."
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- The technique not only helps place the suspect at the scene of
- the crime, but can also suggest what he or she was doing there.
- "One may have some plausible explanation for fingerprints,"
- explains Timothy Berry, a prosecutor in Orlando. "But blood,
- semen, uprooted hair, skin under the fingernails of the victim
- are something else." The information can be so damning that it
- precipitates a confession. In Tacoma last December, a bus
- driver pleaded guilty to rape although the victim, a 57-year-old
- woman with Alzheimer's disease, does not remember the crime.
- DNA analysis established that semen on the woman's
- undergarments belonged to the accused. On the other hand,
- genetic fingerprinting can be equally powerful in establishing
- a suspect's innocence.
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- Still, DNA printing is not yet automatically acceptable in
- court as evidence. Judges now rule on its admissibility on a
- case-by- case basis. But the methodology, which has long been
- used in biological research, is expected to survive legal
- challenges, and the FBI is moving rapidly to adopt the
- technique.
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- Ultimately, forensic experts foresee the creation of
- computerized banks of DNA prints. Washington State's King
- County is wasting no time. Beginning in January, the county
- plans to take DNA samples from all convicted sex offenders. The
- aim: a DNA library that will pinpoint the owners of genetic
- fingerprints left at the scenes of future crimes.
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- By Anastasic Toufexis. Reported by Thomas McCarroll and Raji
- Samghabadi/New York.
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