LOS ANGELES – As the trial of Grim Sleeper serial killer suspect Lonnie Franklin Jr., 63,   began in Los  Angeles February 16, 2016, some people were just tuning in to the details of how investigators finally identified Franklin as the suspect and arrested him in 2010 – decades after the first of 10 young women he’s suspected of killing, was found dead.

The former mechanic is charged with the murders of nine women and a 15-year-old girl.  Most of the victims were sexually assaulted and shot, some were strangled, all were dumped in back alleys or dumpsters in south Los Angeles.

The murders linked to the Grim Sleeper started in 1985.  As far as investigators know, there was a break in the killings in the 90s, and the killer resumed his murderous acts the decade after that.

After so many years, how did investigators end up cuffing Lonnie Franklin Jr.?  

The arrest was the result of familial DNA technology used by California Department of Justice (DOJ) criminalists at the Bureau of Forensics lab in Richmond.  The information they provided to investigators, leading them to Franklin’s son,  was key.  It is that information that led investigators to Franklin.  Following him, they seized a piece of pizza crust he left behind at a restaurant.  This is a case built on the science of DNA.

Below is a conversation by DOJ senior criminalists at the Richmond lab about familial DNA and the Grim Sleeper.

“Many crimes are solved and suspects identified by California DOJ criminalists,” said California Statewide Law Enforcement Association (CSLEA) President Alan Barcelona.  “These are incredibly educated and smart individuals who use science to assist law enforcement in pursuit of criminal justice.  Most of their work goes unnoticed, but the very work they did to help identify the Grim Sleeper suspect, is work they do every single day.  In many instances there simply would be no case, no conviction, without them.”

“DNA is an extraordinarily powerful tool for solving crimes, and this is one of the more spectacular successes,” said Association of Criminalists-DOJ (AC-DOJ) President John Miller.  “It’s really what familial searching is all about: cases where law enforcement has exhausted all its leads, and has nowhere else to turn. I’m really proud of all the DOJ criminalists involved in providing this tool to law enforcement.”