PHOENIX -- Court records unsealed Monday afternoon show the man accused of being Mesa's serial predator admitted to sexually assaulting two women and leaving another for dead.

READ: 5/14/08 - Man Arrested Has 7-Year-Old Son

The document said Trent Benson, 36, stopped short of confessing to the slayings.

Investigators said they received a tip and followed Benson. Detectives said they were able to collect a cigarette butt he had dropped, enabling them to get his DNA.

The document said police matched his DNA to a sample collected from all four victims -- Karen Jane Campbell, 44, and Alisa Marie Beck, 21, who were strangled to death, and two other women who detectives said were sexually assaulted but survived.

Records also show that during an interview with police, Benson admitted to knowing the victims.

One victim said she was beaten unconcious and when she awoke, noticed a camera on the ceiling and several monitors around the room, the document said.

She managed to get away and call police, the document said.

Police said they had Benson under surveillance for about a day before arresting him May 14.