"It shows how important this type of search can be and what it would yield which is a suspect in a case where so many women were killed," said Elizabeth Thompson, director of the Orange County DNA Lab.
It's called a familial DNA search. Lonnie Franklins son's DNA was in a database after being convicted of a felony weapons charge. Investigators noticed it was similar to DNA collected at "Grim Sleeper" murder scenes. The connection then led to Franklin after his DNA was obtained from items he used at a restaurant.
"This is the first partial match or familial match in the state of California, so it's quite significant," said Thompson.
The familial DNA search program came to be in 2008 in California. It faced controversy from some who felt it could invade privacy of family members.
Authorities say Department of Justice officials were concerned about privacy violations. They retested DNA and reviewed the legal aspects before Franklin's arrest.
"We only took data from convicted felons no other form of DNA. We got info, got the man," said California Attorney General Jerry Brown.
Officials also acknowledged work done by Bruce Harrington for fighting to create Calfornia's DNA database from convicts. Harrington's brother and sister-in-law were murdered in their Laguna Niguel home in 1980.
Authorities say the suspect's DNA in that case is linked to at least 12 murders and 50 rapes going back to the 1970s. The Harrington case is one of two from Orange County submitted to the Department of Justice, hoping familial searching might identify the suspect and provide some closure for family members in that case.