A former sanitation worker was sentenced to death on Wednesday for murdering nine women and a teenage girl as the “Grim Sleeper” serial killer who preyed on prostitutes and drug addicts in a Los Angeles crime spree dating back 30 years.

Los Angeles County Superior Court Kathleen Kennedy imposed the death sentence recommended in June for Lonnie David Franklin Jr., 63, by a jury. A month earlier, it had convicted him on 10 counts of first-degree murder and one count of attempted murder.

Franklin was convicted of shooting seven women to death from August 1985 to September 1988, then strangling a 15-year-old girl, and strangling or shooting two other women in a second round of killings between March 2002 and January 2007.

Ho New / Reuters Lonnie David Franklin Jr., a former sanitation worker, has been sentenced to die for murdering 10 people in Los Angeles.

Before Franklin was arrested the killer was dubbed the “Grim Sleeper” because he seemed to have taken a 13-year break between the two spates of murders.

Franklin also was found guilty of attacking an 11th victim, who survived being shot, raped, pushed out of a car and left for dead in 1988. She testified against him at trial.

Prosecutors said Franklin stalked the streets of South Los Angeles, preying on prostitutes and drug addicts in a crime spree beginning at the height of a crack cocaine epidemic in the area. His victims’ nude or partially clothed bodies were found dumped in alleys and trash bins.

Ho New / Reuters These are some of the photographs that were found in Franklin's possession. Police publicly released the photos in a bid to potentially identify additional victims.

Franklin did not testify in his own defense. During the trial, his attorneys sought to raise doubts about DNA evidence and suggested another “mystery man” was behind the killings.

Authorities said after Franklin’s 2011 indictment that they had evidence tying him to several more unsolved slayings, some of which occurred during the presumed lapse in killings.

Prosecutors in the penalty phase of the trial were permitted to present testimony about four such cases.