Two New Laws Restrict Police Use of DNA Search Method

In other cases, detectives can covertly collect DNA from a suspect’s relative by testing an object that the relative threw in the trash.

Maryland’s new law states that when police officers test the DNA of “third parties” – other than the suspect – they must first obtain written consent unless a judge approves misleading collection.

Investigators cannot use any of the collected genetic information, either from the suspect or third parties, to learn about a person’s psychological traits or disease conditions. At the end of the study, all the genetic and genealogical records created for it must be deleted from databases.

And perhaps most consistently, Maryland researchers interested in genetic genealogy must first try their luck with a government-run DNA database called Codis, whose profiles use far fewer genetic markers.

Sir. Holes said this part of the law could have tragic consequences. For old cases, he pointed out, DNA evidence is often very degraded and fragile, and every DNA test consumes some of the precious sample. “Basically, the statute could potentially cause me to kill my case,” he said. And given the rate at which DNA technology is evolving, he added, it is unwise for a law to prescribe the use of a particular type of test.

But other experts called this provision crucial because the potential privacy breach is far more serious for genealogy, which provides law enforcement access to hundreds of thousands of genetic markers, than it is for Codis, which uses only about two dozen markers.

These searches are “similar to the government reviewing all your medical records and all your family records just to identify you,” said Leah Larkin, a geneticist who runs a consulting firm in the San Francisco Bay Area that is largely focused on help adoptees and others find their biological relatives. “I do not think people fully appreciate how much is in your genetic data.”