A convicted Illinois killer was found guilty Wednesday of the murders of five women in Southern California more than two decades ago.

Orange County jurors convicted Andrew Urdiales of five counts of murder with enhancements for attacking a volunteer usher after a college piano concert and picking up four prostitutes, driving them to remote or deserted areas, having sex with them and killing them.

The verdict raises to eight the number of women killed by the 53-year-old former Marine.

Urdiales was previously convicted of killing three women in Illinois in 2002 and 2004. He was given a death sentence that was commuted to life without parole after Illinois barred the death penalty.

He was extradited to California in 2011 to stand trial in the murders of five women in Riverside, Orange and San Diego counties between 1986 and 1995. For these killings, California prosecutors are seeking the death penalty.

The penalty phase of the trial will begin Thursday for jurors to evaluate whether to recommend a death sentence for Urdiales or life without parole.

Attorneys declined to comment publicly on the verdicts before the trial has concluded.

Authorities said Urdiales, who moved to Southern California in 1984 as a 19-year-old Marine, killed four women while in the military and a fifth while vacationing in Palm Springs in 1995.

He attacked 23-year-old Robbin Brandley after a jazz piano concert in 1986 at an Orange County community college and stabbed her to death in the parking lot. Two years later, he picked up Julie McGhee, a 29-year-old prostitute, and drove her to a remote area, had sex with her, shot her in the head and left her body in the desert, authorities said.

Urdiales went on to attack and kill three more Southern California women and three Illinois women who were working as prostitutes, authorities said.

The California murders went unsolved for more than a decade until Urdiales was arrested after he returned home to Illinois.

Authorities stopped Urdiales in 1996 and found a weapon in his truck that he wasn't allowed to carry, prosecutors said. The next year, authorities matched the weapon to the one used to kill the Illinois women and arrested him for those murders.