The photos picturing the woman and Gargiulo were taken between 2001 and 2003, cops tell PEOPLE

The Los Angeles County Sheriff’s Department is trying to identify a woman pictured in photos with alleged serial killer Michael Gargiulo who they believe might have been killed by him.

Detectives found the photos on Gargiulo’s hard drive in 2008 after he was charged in Los Angeles with the murder of two women and the attempted murder of another. Gargiulo, a former bouncer and HVAC repairman, has also been charged with a murder in Illinois. (One of Gargiulo’s alleged murder victims, 23-year-old Ashley Ellerin, was dating actor Ashton Kutcher when she was stabbed to death in 2001.)

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Los Angeles County Sheriff’s Department detective Mark Lillienfeld tells PEOPLE that the woman in the photos “resembles some of the victims of the murders of which he has been charged.”

Lillienfeld adds, “It’s possible, and we’re hoping, that she is fine and living her life. We’d simply like to identify her and confirm that she’s OK.”

Lillienfeld says the photos of Gargiulo and the mystery woman were possibly taken in California between 2001 and 2003.

The sheriff’s department initially released the photos after Gargiulo’s arrest, but the woman has never been identified.

“We got a couple of she looks like my cousin calls,” says Lillienfeld. “But we just weren’t able to identify this particular woman.”

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Gargiulo’s Alleged Crimes

Ashley Ellerin was found stabbed to death by her roommate in her Hollywood bungalow on the morning of February 22, 2001. The night before, she had plans to meet up with Kutcher for a drink. According to police, Kutcher arrived at 10:45 p.m, but Ellerin didn’t answer the door. Before he left, he peered through a front window, and saw what he believed was red wine stains on the floor. Police later determined the stains were blood.

In December of 2005, 32-year-old Maria Bruno, a mother of four, was found in her bed with her throat and chest slashed just 10 days after she moved into a first-floor unit in a gated apartment complex in which Gargiulo also lived. Detectives discovered a blue surgical bootie that the killer wore outside her apartment.

Then, in 2008, Michelle Murphy, a Santa Monica woman was attacked inside her apartment while she was sleeping. She woke up to someone stabbing her in the chest, shoulder and right arm but was able to kick him off her. Her attacker cut himself during the fight and fled.

Gargiulo was also charged in 2011 with the 1993 murder of Tricia Pacaccio, an Illinois teen who was found stabbed to death on her porch in 1993. Gargiulo, who lived five doors down, was friends with Pacaccio’s younger brother.

Gargiulo, now 39, is currently in Los Angeles County jail awaiting trial on the murder and attempted murder charges, for which he has a pre-trial hearing tomorrow. He has denied any involvement in the murders in Los Angeles and the killing of Pacaccio.