Brown's Forensic Experts Identify Grim Sleeper Serial Killer Suspect Through Unprecedented Use of Familial DNA
LOS ANGELES – In less than two years, a new and controversial DNA searching program launched by Attorney General Edmund G. Brown Jr. has proven its worth by nabbing a man suspected of being the “Grim Sleeper” who carried out the murders of at least 10 women in the Los Angeles area over the past 25 years.
Lonnie David Franklin, Jr., 57, of Los Angeles, was arrested yesterday on multiple murder counts after the state DNA lab uncovered a DNA link between the murder-scene material and Franklin’s son. Last year, the son was convicted of a felony weapons charge, and his DNA was collected and sent to the state DNA data bank for the first time.
“In the face of a multitude of objections, we’ve crafted a balanced policy to respect the rights of citizens and at the same time deploy the most powerful DNA search technology available,” Brown said. “Forensic scientists at our Richmond crime lab have developed unique computer software and rigorous protocols that can link a family member of a convicted offender with DNA taken from a murder or rape scene. The successful match in this case demonstrates the extreme importance of this new forensic procedure.”
California became the first state to adopt a familial search program in 2008. It has been used only ten times since its inception in November 2008. The initial familial search under the new program that same month was aimed at finding the “Grim Sleeper” suspect, but it failed to find a relative in the database. A second search initiated on April 28, 2010, was successful because, in the meantime, Lonnie David Franklin’s son had been convicted, his DNA analyzed and linked to the crime scenes in accord with California’s unique familial search procedures.
The suspect would still be at large except for the familial search program.
Familial search works by searching the crime scene sample against convicted offenders in the state database to see if they could be related to the crime scene sample. The convicted offenders are compared to the crime scene sample by looking at how many of the DNA markers are shared and how rare the markers are.
Last month, investigators established a connection between Franklin’s son's DNA and DNA taken from the murder scenes. After corroboration with other information, such as google mapping and where Lonnie David Franklin was living during the time the murders occurred, it was determined that Lonnie David Franklin was a viable suspect.
The Los Angeles Police Department then confirmed our finding by taking the suspect’s personal DNA.
Familial DNA searches are done under rigorous guidelines established by Brown’s office. They are only allowed in major violent crimes when there is a serious risk to public safety and all other investigative leads have been exhausted.
“Now we’ve proven how important this forensic technology is by tracking down a suspected serial killer who terrorized Los Angeles for more than two decades,” Brown added.
By following rigorous protocols, scientists from the DOJ Bureau of Forensic Services were able to identify an offender in its DNA Data Bank who did not match the crime scene DNA profile of the Grim Sleeper, but shared sufficient genetic characteristics that ranked him high on a list of potential first-order male relatives, such as a father/son relationship or a brother/brother relationship.
Brown’s lab conducted further testing of the DNA on the Y-chromosome of the offender and compared it to the crime scene Y-chromosome DNA profile, in order to corroborate or disprove the theory that they are close relatives. The Y-chromosome profiles matched, indicating a strong possibility that they are paternal relatives.
State agents then reviewed additional information to corroborate or disprove the theory of kinship. The information collected showed that Franklin was a viable suspect in the murders.
Finally, the Familial Search Committee, a body created to verify familial DNA search results, reviewed all available data. The Department of Justice then provided the name of the database offender to the Los Angeles Police Department as an investigative lead, asserting a reasonable probability that the offender, while not the perpetrator, is a close relative.
The Grim Sleeper
The serial killer known as the “Grim Sleeper” is believed to have committed at least eleven murders and one attempted murder in Los Angeles since 1985. The crimes have been linked by DNA evidence, but until the familial DNA match, there was no suspect in the case.
The Grim Sleeper’s eleven victims include ten women and one man between the ages of 14 and 36 years. All of the victims were strangled or shot and most were dumped in alleys in Los Angeles.
California’s DNA Data Bank
At California’s DNA Data Bank, formally established in 1990, offender and arrestee samples are analyzed every day at the Jan Bashinski DNA Laboratory located in Richmond, CA. Each day, local law enforcement agencies submit offender and arrestee samples in an effort to solve an unsolved case such as a burglary, sexual assault or homicide. These samples are analyzed and uploaded into CODIS (Combined DNA Index System) otherwise known as the CAL-DNA Data Bank.
The state’s forensics laboratory has the fourth largest DNA database in the world with more than 1.5 million convicted offender and arrestee DNA profiles and a hit rate of more than 300 hits per month. Each month the lab processes up to 25,000 and 30,000 offender/arrestee samples. Weekly, offender/arrestee sample DNA profiles are uploaded to the DNA database and searched against forensic evidence DNA profiles from crime scenes submitted by local California crime laboratories and the rest of the nation.