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Can police collect DNA when someone is arrested? Supreme Court to decide.

At issue in the case the Supreme Court considered Tuesday is whether collecting DNA from an arrestee without first obtaining a warrant is an unreasonable search under the Fourth Amendment.

By Staff writer / February 26, 2013

This photo shows the covered Supreme Court building in Washington in September 2012, with a protective scrim, as work continues on the facade.

Alex Brandon/AP/File



The US Supreme Court heard argument Tuesday in a case testing whether government officials can routinely collect a person’s DNA at the time he or she is arrested and then use that DNA sample to try to link the individual to unsolved crimes.

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At issue in the case, Maryland v. King (12-207), is whether taking a DNA sample from an arrestee without first obtaining a court-authorized warrant is an unreasonable search under the Fourth Amendment.

DNA has become an essential law-enforcement tool, not just in its ability to conclusively identify an individual but, more important, through its ability to conclusively link suspects to cold cases.

In effect, DNA is becoming in the 21st century what fingerprinting was to the 20th – except better.

But there’s a problem. Unlike a fingerprint, DNA material contains a plethora of highly personal information bound within a person’s genetic code. When the government seizes DNA material, it is taking control of more than just the ability to isolate an identifying pattern unique to one individual. With advances in genetic science, DNA might someday reveal information about an individual’s susceptibility to future diseases and perhaps even personality traits, scientists say.

Several justices expressed concern that seizing a DNA sample from an individual to solve cold cases is a search under the Fourth Amendment. What justifies the state taking such action without a warrant?, they wanted to know.

Katherine Winfree, Maryland’s chief deputy attorney general, told the justices that the state did not need to obtain a warrant to collect DNA samples from arrestees because people in police custody have already surrendered a substantial amount of their liberty and privacy.

“That can’t quite be right,” Justice Elena Kagan countered. “Assume you’ve been arrested for something; the state doesn’t have a right to go search your house for evidence of unrelated crimes.”

She added: “Just because you’ve been arrested doesn’t mean that you lose your privacy expectations ... that aren’t related to the offense that you’ve been arrested for,” Justice Kagan said.

“What we’re seizing is not evidence of crime,” Ms. Winfree responded. “What it is is information related to that person’s DNA profile.”

One issue in the case is the purpose of collecting the DNA. Maryland uses it to help identify the arrestee, Winfree said. But the state also uses it to solve unsolved crimes.

Justice Sonia Sotomayor picked up the same line of questioning. “You are going to have to tell me why searching their person is different than searching their home or car,” she said.

Winfree replied that people in police custody have a reduced expectation of privacy that eliminates Fourth Amendment protections for a person’s DNA. Collecting the DNA sample, she added, is minimally intrusive, involving a buccal swab from the inside of an arrestee’s cheek.

Michael Dreeben, deputy US solicitor general, told the justices that taking a DNA sample was substantially different from searching a home for evidence of a crime. “It is far more like taking a fingerprint,” he said.


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