Lonnie Franklin Jr is accused of killing 10 women, all of whom were found in alleyways within a few miles of his home in downtown LA as we reported here.
All the victims, some of whom were prostitutes, were shot, strangled or both and most had been sexually assaulted.
The killer was dubbed 'the grim sleeper' because of the long gaps between the deaths, which began in the 1980s and ended in this century.
Cops were baffled for years, but they finally linked Franklin to the crimes after a DNA database showed a convicted felon, his 28-year-old son, matched the genetic blueprint found at 15 crime scene locations.
When they arrested him they found photographs and videos of another 100 women at his home.
Franklin, a mechanic, was arrested and indicted in July 2010 and indicted and now cops are investigating him in connection with another 250 murders.
The LA Times is reporting however that they will not immediately seek additional charges in the other killings because they don't want to complicate the case against Franklin as it moves toward trial.
Meanwhile, Franklin's attorney, Louisa Pensanti, said the new allegations are false.
She also accused authorities of making the allegations public in order to infect the jury pool.