The LAPD plans to release images of 160 women taken by the alleged " Grim Sleeper" on Thursday in the hope that family or friends will recognize them and contact authorities.

In July, when Los Angeles police arrested Lonnie Franklin Jr., the man accused of being the notorious "Grim Sleeper" serial killer, they searched his South L.A. home for incriminating evidence and found nearly 1,000 still photographs and hours of video showing women, almost all of them partly or completely nude and striking sexually graphic poses.

Detectives have spent months trying to identify the women to determine whether they are alive and to learn how they came to be photographed by a man charged with sexually assaulting and killing 10 women during a crime spree that spanned two decades.

The attempt has proved fruitless prompting the LAPD to release the images of 160 women in the hope that family or friends will identify them and contact investigators.

Back in August, 57-year-old Franklin pleaded not guilty to murder charges in a downtown Los Angeles courtroom.

Franklin was dressed in an orange prison jumpsuit and had his hands shackled to his waist. The pleas were entered on his behalf by his attorney. Franklin only spoke to answer procedural questions.

About 30 family members and friends of some of the victims of the "Grim Sleeper" attended the emotional hearing. Some were seen crying as they left the courtroom.

The retired auto mechanic was arrested at his South Los Angeles home July 7 after DNA evidence linked him to the 10 murders. Investigators said they were trying to tie him to dozens more.

Franklin is being held without bail.

Prosecutors have not yet decided whether they'll seek the death penalty.

Superior Court Judge Hilleri G. Merrit has said the trial process could last three years.

Private attorney Louisa Pensanti, who is working for free and said she has experience handling multiple murder cases, took over for the public defenders assigned to Franklin's case.

She told reporters outside the courthouse that she would assemble a team of lawyers to look through more than 8,000 pages of documents provided by prosecutors.

Franklin's arrest ended a 25 year investigation into the deaths of 11 people dating back to 1985.

He has been charged with 10 counts of murder, one count of attempted murder and special circumstance allegations of multiple murders that could make him eligible for the death penalty if convicted.

See the 'Grim Sleeper' Victims

Police say Franklin was linked to the crimes using a relatively new and controversial forensic technique known as 'Familial' DNA searching.

"Familial" searching allows investigators to look for close DNA matches in relatives when the suspect's DNA profile is not in the state database.

According to police, a DNA sample taken from his son in an unrelated case was found to bear a close resemblance to DNA found on the victims.

Detectives then used a discarded cup with Franklin's DNA to make the link, officials said.

Franklin worked as an attendant working on LAPD cars in 1981, and then later worked in the sanitation department. He has since been working as a private mechanic.

The 'Grim Sleeper' is accused of murdering 10 women and one man from 1985 to 2007.

After 1988, the killer did not commit any known homicides until 2002, giving the suspect his 'Grim Sleeper' nickname.

He last struck on Jan. 1, 2007.

A 12th victim escaped after she was shot and raped.

The 14-year hiatus between the two distinct sets of killings correspond to a time when Franklin was on disability, a law enforcement source said.

All the bodies were found outdoors, often in alleys a few miles south of downtown Los Angeles.

The victims were shot, strangled or both, usually after some kind of sexual contact.

Ten victims were women and several were prostitutes.

Police have said it's possible the male victim, Thomas Steele, who was shot in 1987, was a friend of another victim or discovered the killer's identity.

Franklin has twice been convicted of felonies, according to court records, both for receiving stolen property.

One was in 1993 and the other was 2003.

He served a year in jail for the first conviction and was sentenced to 270 days in jail in the 2003 case.

In 1997, he pleaded guilty to one count of misdemeanor battery.

As part of a plea deal, a charge of false imprisonment was dropped, according to court records.

In 1999, he was convicted of misdemeanor assault with a deadly weapon. He was sentenced to 90 days in jail.

Details of that case were not immediately available.

The "Grim Sleeper" was described in 1988 by the surviving victim as black, in his 20s, between 5-foot-8 and 5-foot-10, around 160 pounds, soft-spoken, articulate, with neatly trimmed hair and a pockmarked face.

Police released new composite sketches of the "Grim Sleeper" in December showing what the suspect may look like now.

In February, detectives released a recording of a 1987 emergency call as they searched for a suspect.

The witness called from a pay phone to say he had seen a man remove a woman's body from a blue and white 1976 Dodge van.

The man told the dispatcher the van's license plate was 1PZP746, and police located it about 30 minutes later at the now-defunct Cosmopolitan Cathedral.

The body the witness reported seeing was that of Barbara Ware, a 23-year-old with a history of prostitution who was found shot to death in a South Los Angeles alley in 1987.

When asked his name, the caller said "I know too many people," and then hung up.