When I think of DNA evidence being used in a criminal case, I think of the hundreds of men who were freed after wrongful convictions through DNA testing with the help of groups like the Innocence Project.

But the arrest of suspect Lonnie Franklin Jr., 57, in the "Grim Sleeper" serial murder case in Los Angeles is shining a light on a new and controversial use of DNA evidence -- tracing DNA from family members to link a suspect to a crime.

Police in Los Angeles had little to go on in the perplexing case of the Grim Sleeper, a killer who earned the name because he apparently killed several young women in the mid-1980s then stopped killing for a period of about 14 years before resuming his murder spree.

Los Angeles police spent more than 20 years using traditional investigating methods to track the murderer without results. It wasn't until they decided to run DNA evidence from murder scenes through a database of more than a million of potential suspects that things got interesting.

Franklin's DNA was not among the million of samples tested. But the DNA of his son, who had been added to the database recently due to a felony weapons conviction, was among the samples. The DNA of Franklin's son registered a near match or a familial match.

Police then cross-checked relatives of Franklin's son through birth certificates and arrest records and saw Franklin as a possible suspect.

But they still needed a sample of Franklin's DNA to make a match. And police got it when they used an undercover officer who posed as a worker in a diner to collect tableware, napkins, glasses and discarded pizza crust used by Franklin at a restaurant where he ate.

DNA samples from the utensils and pizza matched the DNA from the murder scenes, and Franklin was charged. His arraignment is scheduled for Aug. 9.

Some advocates for the victims believe the case didn't gain the notoriety it deserved because the victims were young black women. But to me, the fact that police stayed on the killer's trail for more than 20 years and employed the groundbreaking use of DNA evidence shows that familial DNA is the true story here.




When I first heard about familial DNA, I only thought of the technique being used in relatively minor cases. But to see it used for the first time in a case of such import makes me pause.

Have they really got the technology down to the point that a scrap of DNA can identify me if my brother or daughter committed a crime? It's hard for me to grasp.

I believe that civil libertarians are going to have to keep close watch on the development of this technology.

While all indications are that the Los Angeles police used the tool and good old-fashioned detective work to find a guilty man, I can imagine a scenario where a less diligent police team could use familial DNA to go after an easy (i.e., poor) suspect just because he has a family member who is a criminal.

Either way, bad guys might have to live by a new ethos in light of the new use of DNA evidence. Just one criminal per family, please.