Cops track crims through family DNA

A CONTROVERSIAL NEW law in California is allowing police to track down criminals by trawling through the state's DNA database looking for profiles of close family members.

The LAPD hope that in cases where a perp’s DNA doesn’t match up to any DNA profiles in the database, family members whose DNA is on file may be able to give detectives a clue to his/her whereabouts.

The method is not a new one, having started out in Britain several years ago, but California's newly-approved familial searching policy will be the most far-reaching one in the US and is already making privacy advocates itchy.

Stanford University law professor, Hank Greely, noted "There is kind of a queasiness about having the sins of your father come back to haunt you," and that bulldozing family privacy because of a possible genetic relationship to an unknown suspect “feels like we're holding people responsible for the crimes of their family."

But in the UK, the family DNA trawl has led to the arrests of 18 dangerous criminals who would otherwise have probably never been apprehended, including the infamous 'shoe rapist'.

Jerry Brown, Attorney General of California told the LA Times that the case for familial searching was compelling, noting the state saw about 2,000 murders a year. "That is a lot of killing. When you see it and see the victims and have to go to the funerals, it is pretty serious stuff," he said.

The way the system will work will be through a list of possible relatives to a suspect, ranked in order of genetic similarities. The list can be cut down with more extensive genetic testing and by reviewing public records to determine ages, addresses and names of family members. State officials reckon this could put the odds of finding the serial killer at about one in 10.

Though it’s true that unrelated people can share a few genetic markers by chance, parents and children usually share about half, as do siblings.

We imagine the situation playing out as follows:

Policeman: “Scuse me sir, but we have reason to believe one of your close relatives is a mass murderer... any idea who it might be?”

Relative: “Well uncle Albert is always a bit strange after a sherry at the Xmas party. And he likes to brutally murder the odd prostitute, but apart from that he's a lovely man... wouldn't hurt a fly”. µ

L'Inq
LA Times