So far they have charged Lonnie Franklin Jr with the murders of 10 women all of whom were shot, strangled or both and then dumped in alleyways within a few miles of his home.
Franklin, a mechanic, has however denied killing any of the victims, some of whom were prostitutes and all of whom died are some kind of sexual contact.
The killings got their "Grim Sleeper" tag because of an apparent long gap between some of the deaths, which began in the 1980s and extended into the 2000s.
But police now believe there was never a break in the killings and they are continuing to try and identify women in as many as 52 photos found stashed in a fridge in Franklins, South LA house.
LAPD Cmdr. Andrew Smith said: "We just want to make sure nothing fell through the cracks."