Nicknamed “The Grim Sleeper,” a Los Angeles serial killer later identified as Lonnie David Franklin Jr. managed to hide from the police for more than 25 years. He acquired the nickname because between 1985 and 2007, his crimes were committed interspersed with long periods of inactivity. Using the DNA of the killer found on the victims, investigators conducted an initial search of the CODIS database of convicted killers. The search of the evidence DNA did not turn up a hit. More killings started again in 2002, but no suspect was identified. The case was reopened in 2008 when California became the first state to authorize familial searching of CODIS for partial matches. Familial searching permitted scientists to look for partial “matches” to the killer’s DNA and the DNA in the file of convicted offenders. The familial search found a 50 percent match with Lonnie David Franklin Jr.’s son, Christopher Franklin, whose DNA was in CODIS due to an earlier felony weapons charge. Because the markers on the Y chromosome of Christopher’s DNA were consistent with those on the Y chromosome of “The Grim Sleeper,” the investigators began focusing on Lonnie David Franklin Jr. A law-enforcement officer posed as a waiter at a pizza restaurant and obtained DNA evidence from Lonnie’s utensils and a partially eaten slice of pizza. The evidence DNA was consistent with the killer’s DNA. In 2010, the Grim Sleeper was arrested and convicted. Familial searching of CODIS helped the police identify the killer and put a stop to the murders.
