by liberal japonicus
Maybe I'm reaching for a cute headline, but that's what seems to have happened.
A cursory reading suggests that they compared the DNA they had with DNA profiles on genealogical sites to get a familial match. The article references the Grim Sleeper case.
On July 7, 2010, the Los Angeles Times reported that an arrest had been made. District Attorney Steve Cooley identified the suspect as 57-year-old Lonnie David Franklin Jr. (born August 30, 1952), a mechanic who worked between 1981 and 1988 for the City of Los Angeles in the sanitation department and briefly for the police department. Franklin was identified for arrest, at least in part, on familial DNA analysis.
Police had found no exact match between DNA found at the crime scenes and any of the profiles in California's DNA profile database, so they searched the database for stored profiles that demonstrated sufficient similarity to allow police to infer a familial relationship. They found similar DNA belonging to Franklin's son, Christopher, who had been convicted of a felony weapons charge. According to Los Angeles District Attorney Steve Cooley, detectives then used a piece of discarded pizza with Franklin's DNA to make the link. One Los Angeles undercover police officer pretended to be a waiter at a restaurant where the suspect ate. He collected dishes, silverware, glasses, and pizza crusts to obtain DNA. The identification was used to arrest Franklin after his DNA was obtained and deemed a match. Saliva found on the victims established a DNA match linking Franklin to the deaths.
Very curious what folks here think of all this and since the last thread is approaching 200 comments, I'd put this up.