Should cops test DNA of criminals' relatives?

A new proposal calls for expanded DNA sampling, including taking DNA samples of the families of known criminals, in order to improve law enforcement, the Washington Post reports.

Based on the UK's more permissive DNA testing policies, the report in Science concludes that since close relatives of criminals are more likely than other to be lawbreakers (in the US 46% of jail inmates had a close relative who had been incarcerated at some point) and because close relatives have similar DNA, expanded DNA databases will help finger culprits.

In one recent case, for example, a specimen from a 1988 murder scene was found to have a DNA pattern similar to that of a 14-year-old boy whose DNA was on file with the police. Investigators obtained a sample from the boy's uncle, which perfectly matched the crime scene specimen and led to his conviction.

The new analysis, published today in the online edition of the journal Science, is the first to use sophisticated computer models to predict just how useful such "familial" searches may be.

The suggestion raises rather substantial privacy issues.

If I give up a sample, does that mean I've also committed all my blood relatives to a search?" asked Carol Rose, executive director of the American Civil Liberties Union of Massachusetts. "That's where the technology is moving faster than the law."

Familial testing would also amplify racial inequities in the criminal justice system, which already focuses disproportionately on blacks, said Troy Duster, a New York University sociologist.