Familial DNA Searching: Early Breakthroughs

The Grim Sleeper

Across the Atlantic, initial adoption of familial DNA searching was slower than in the UK. Although the Denver, Colorado Police Department began studying the technique in 1999, California became the first state to make familial DNA searching legal in 2008. Cases in which the technique was employed had to meet two criteria: 1) the crime scene DNA profile had to be a single-source profile; and 2) all other investigative leads must have been exhausted.


The first—and arguably the most infamous—test of familial DNA searching in California was in pursuit of a serial killer known as the Grim Sleeper. The nickname derives from the 13-year break that the perpetrator apparently took after a killing spree that started in 1985.


Beginning in 2001, as part of an effort to implement new DNA analysis methods, the Los Angeles Police Department re-examined several cold cases. Continuing efforts on the Grim Sleeper case identified a DNA match among three victims killed in 1987, 2002 and 2003. Although familial DNA searching was used in 2008, it failed to provide any matches. However, the following year, the arrest of Christopher Franklin in a felony weapons charge provided a DNA sample that resulted a partial match to the Grim Sleeper’s DNA profile. Further investigation led to the arrest of Lonnie David Franklin, Jr—Christopher’s father. Lonnie Franklin’s trial began on February 16, 2016, and he was convicted on all counts of murder and attempted murder, receiving a death sentence on June 6 that year. The case captured so much public interest that a documentary film was released in 2014, Tales of the Grim Sleeper.


[https://www.rottentomatoes.com/m/tales_of_the_grim_sleeper/]

For more information on the Grim Sleeper case, see our interview with Rock Harmon, retired Senior Deputy District Attorney for Alameda County, California.

[https://www.ishinews.com/catching-the-grim-sleeper-an-interview-with-rock-harmon/]