A breakthrough that led to the arrest of Los Angeles’ “Grim Sleeper,” a serial killer who has murdered at least 10 people, may also provide a bigger breakthrough in the use of familial DNA to solve crimes for which the DNA database fails to find a match.

Only Colorado and California currently have laws specifically allowing the use of familial DNA match, and the practice has drawn criticism from privacy advocates who fear that innocent family members will be targeted if they have the misfortune of being related to a criminal.

California’s policy restricts the practice to major, violent crimes in which all other investigative techniques have proved fruitless. This case was a perfect test for the policy.

Investigators tried for years to solve the case of the Grim Sleeper who committed the majority of his killings in the 1980s but after a 13-year absence restarted his spree, the latest murder occurring in 2007. This spring Los Angeles police asked the state to look for a DNA profile similar enough to be a possible relative of the killer, and after several tests, identified the suspect’s son.

The after effects of this case and its use of familial DNA will surely set precedents for its future use as well as new policies as other states adopt the process.

Sources: Los Angeles Times, The New York Times