A bench trial is scheduled to begin Monday for a man accused of sexually attacking and fatally stabbing two young women in separate killings nearly 30 years ago near a metro Phoenix canal system.

Bryan Patrick Miller, 49, is charged with two counts each of first-degree murder, kidnapping and attempted sexual assault. Prosecutors said the state is seeking the death penalty if Miller is convicted.

He waived his right to a jury trial so a Maricopa County Superior Court judge will decide Miller’s fate. Miller is accused of killing 22-year-old Angela Brosso in November 1992 and 17-year-old Melanie Bernas in September 1993.

Brosso and Bernas both disappeared while riding their bicycles along the Arizona Canal in north Phoenix. Authorities said Brosso’s body was found nude and decapitated in a field near a bike path that’s adjacent to the canal.

Ten months later, Bernas’ body was discovered floating in the canal. Authorities said DNA evidence collected in the aftermath of both crimes showed the attacks were linked to the same suspect.

Miller was arrested for the murders in 2015, but denied any involvement although he acknowledged living in the vicinity of the killings at the time and said he rode his bike on paths in the area, according to Phoenix police.

It wasn’t until nine months ago that Miller wasn’t found mentally competent to stand trial.