In other cases, detectives may surreptitiously collect DNA from a relative of a suspect by testing an object the relative threw in the trash.
Maryland’s new law says that when police test the DNA of “third parties” – people other than the suspect – they must first get their consent in writing, unless a judge approves the deceptive collection.
Investigators cannot use any of the genetic information collected, whether from the suspect or from third parties, to learn more about a person’s psychological traits or predispositions to illness. At the end of the investigation, all genetic and genealogical records that have been created for her should be deleted from the databases.
And perhaps most importantly, researchers in Maryland interested in genetic genealogy should first try their luck with a government-run DNA database called Codis, whose profiles use far fewer genetic markers.
Mr 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 each DNA test consumes part of this precious sample. “In essence, the law could potentially cause me to kill my case,” he said. And given the speed at which DNA technology is evolving, he added, it is not wise for a law to mandate the use of a particular type of test.
But other experts have called the provision crucial because the potential breach of privacy is much more serious for genetic genealogy, which gives law enforcement access to hundreds of thousands of genetic markers, which ‘it is not for Codis, who only uses about twenty markers.
This research is “the equivalent of the government looking at all of your medical and family records just to identify you,” said Leah Larkin, a genetic genealogist who runs a consulting firm in the San Francisco Bay Area who is largely focused on helping adoptees and others find their biological parents. “I don’t think people fully appreciate everything in your genetic data.”