DNA Turns Relatives Into Genetic Informants

A Washington Post article, “From DNA of Family, a Tool to Make Arrests,” points to the increasing efforts to look for partial matches in DNA databases that might implicate close relatives.

This is a disturbing development, since DNA, like other forensic evidence, isn’t as foolproof as its image in the popular imagination indicates. There have been cases of false matches of DNA, such as this one in England, this one in Germany, and one I recall in New Zealand. Worse, since US lab error rates (false positives and technician error, such as switching samples or miscataloguing someone in a database) are not captured, errors are almost certain to be higher than widely believed. Without this information, the public and defendants cannot know for certain whether this is a cause for concern. An article from the Observer on the UK’s experience suggests the reservations are warranted:

The DNA database is not a perfect weapon. Last year 1,500 administrative mistakes were discovered and at least 100 inaccuracies pertaining to individuals. That means there is a real possibility of people being convicted of crimes they did not commit. Given the chaotic state of government databases, it must be obvious….. that administrative errors would be vastly increased if the database were to be expanded by a factor of about 13, from 4.5m to 60m.

Needless to say, expanding the scope of searches by looking for partial matches compounds the potential for false positives. However, at least for now, this procedure is sufficiently controversial that it doesn’t have a green light everywhere. Yet. Welcome to our total surveillance society.

More troubling, I did not see a mention in this article of the issue of errors, so it unwittingly promotes the idea that DNA testing is infallible . From the Washington Post:

He was a church-going father of two, and for more than 30 years Dennis Rader eluded police in the Wichita area, killing 10 people and signing taunting letters with a self-styled monogram: BTK, for Bind Torture Kill. In the end, it was a DNA sample that tied BTK to his crimes. Not his own DNA. But his daughter’s.

Investigators obtained a court order without the daughter’s knowledge for a Pap smear specimen she had given five years earlier at a university medical clinic in Kansas. A DNA profile of the specimen almost perfectly matched the DNA evidence taken from several BTK crime scenes, leading detectives to conclude she was the child of the killer. That allowed police to secure an arrest warrant in February 2005 and end BTK’s murderous career.

The BTK case was an early use of an emerging tool in law enforcement: analyzing the DNA of a suspect’s relatives. In the BTK example, police had a suspect and were looking to tie him to the crime. But now, states are moving to conduct familial searches of criminal databases, looking for close-to-perfect matches with DNA from crime scenes. A partial match with a convicted criminal could implicate a brother or daughter or father of the convict. Such searches, advocates say, constitute a powerful law enforcement tool that, experts say, could increase by 40 percent the number of suspects identified through DNA.

As things stand in some states, lab analysts who discover a potential suspect in this way may not be permitted to share that information with investigators. Such a policy, said William Fitzpatrick, a New York state district attorney, “is insanity. It’s disgraceful. If I’ve got something of scientific value that I can’t share because of imaginary privacy concerns, it’s crazy. That’s how we solve crimes.”

But the technique is arousing fierce objections from privacy advocates, who maintain that it turns family members into genetic informants without their knowledge or consent. They complain that it takes material collected for one purpose and uses it for another. And with the nation’s DNA database disproportionately comprised of minority offenders, they say, it amounts to placing a class of Americans under greater scrutiny merely because their relatives have committed crimes.

“If practiced routinely, we would be subjecting hundreds of thousands of innocent people who happen to be relatives of individuals in the FBI database to lifelong genetic surveillance,” said Tania Simoncelli, science adviser to the American Civil Liberties Union.

Nonetheless, California, which maintains the world’s third-largest criminal DNA database with more than 1 million samples, will soon become the first state to adopt a protocol to allow for familial searches. Last week, Colorado performed a test run of familial search software on its criminal database. In Massachusetts, officials say they plan to develop a policy to allow familial searches.

The technique is being adopted as states and the federal government expand their databanks to include profiles of people who have been arrested but not convicted of certain crimes.

Only Maryland has expressly banned familial searching in a law adopted this month to expand its DNA database to include anyone charged with a violent crime. The FBI, which maintains the world’s largest forensic DNA database with almost 6 million profiles, said it has so far refrained from adopting the technique because of concerns about constitutional challenges….

An advisory group to the FBI has proposed a final policy that goes further, recommending that partial matches be subjected to additional DNA testing and statistical analysis that would help investigators home in on relatives of people in the federal database.

The key is intent, Callaghan said. The bureau is “not deliberately trolling the database looking for relatives,” he said.

Heightening privacy concerns are the growing number of local jurisdictions that maintain DNA databases not restricted to criminals. Some include the DNA of victims, suspects or even lab workers. Such collections, which critics call “rogue databases,” are barred from inclusion in state and national databases, but rules about their use by law enforcement agencies are unclear.

The Supreme Court has repeatedly held that authorities may not conduct searches for general law enforcement purposes without suspicion about individuals. Although convicted criminals have a diminished expectation of privacy, searching a database for unknown relatives might violate that principle, said Jeffrey Rosen, a George Washington University law professor.

“The idea of holding people responsible for who they are rather than what they’ve done could challenge deep American principles of privacy and equality,” he said. “Although the legal issues aren’t clear, the moral ones are vexing.”….

Other states and localities maintain “offline” DNA databanks of samples taken from victims or suspects never charged with a crime. Such databases, which also exist in New York, are a violation of the constitutional ban on unreasonable search and seizure, said Barry Scheck, a commissioner on New York state’s Forensic Science Review Board. “If I get a sample from you and I don’t tell you I want to put it in the database, that violates the scope of the Fourth Amendment,” he said.

Prince George’s County, for example, maintains a database with DNA profiles of both victims and suspects. Such local databases “have literally no oversight and regulation and yet are pushing the boundaries farther than anyone could imagine,” said Patrick Kent, chief of the Maryland public defender’s forensic division. “I do not think that victims of crime would be pleased to know that in addition to having been a victim, their DNA profile has been surreptitiously placed into a DNA database.”