A man dubbed the "Hollywood Ripper" was found guilty Thursday of the murders of two women, including a student who was due to go out with actor Ashton Kutcher the night of her death.

Michael Gargiulo, 43, was convicted of two counts of first-degree murder by a Los Angeles jury who deliberated for four days before reaching their verdict.

Prosecutor Dan Akemon had told jurors that Gargiulo targeted the women in "frenzied knife attacks," referring to him as a "stone-cold serial killer who preys on women."

Gargiulo's lawyers said he denied the killings.

They said there was no evidence Gargiulo was at the scene of the two murders, and indicated that his dissociative identity disorder could have caused him to go into a "fugue" state during a separate attack on a third woman who survived.

The trial will move next week to a second phase to assess if Gargiulo was sane at the time of the killings, before sentencing then takes place.

Gargiulo could face the death penalty.

He is also awaiting a separate trial for the earlier 1993 killing of a third woman in the state of Illinois.

Prosecutor Akemon said Gargiulo targeted women who lived near him and waited for the perfect opportunity to attack them at night in or near their homes in "totally planned killings."

The murdered women had injuries to their breasts, and one was found nearly decapitated, he said.

"Two and a Half Men" actor Kutcher told jurors he had gone to victim Ashley Ellerin's home in Hollywood in 2001 to pick her up for a date, but had arrived late and nobody had answered the door.

He said he had looked through a window and seen what he thought was red wine spilled on the floor before leaving, assuming she had already gone out.

Kutcher said he and Ellerin, a 22-year-old fashion design student, were acquaintances.

The second victim, 32-year-old Maria Bruno, was killed in her Los Angeles area apartment in 2005.

Gargiulo was arrested in Santa Monica in 2008 following an attack on another woman who survived being stabbed eight times in her home.

He was also found guilty of attempted murder for that case Thursday.