Rasaan Raymon Patton.

Rasaan Raymon Patton. (Courtesy Orange County district attorney's office / June 29, 2012)

A registered sex offender was convicted Thursday of sexually assaulting a 17-year-old girl on the side of a road in Huntington Beach, authorities said.

Rasaan Raymon Patton, 31, attacked the girl in June 2008 after he crashed into a minivan she was driving, which forced her to pull over, according to the Orange County district attorney's office.

The victim was able to escape after Patton was startled by passing vehicles, prosecutors said. She reported the assault to Huntington Beach Police.

Patton was arrested at his Riverside County home in April 2009 after investigators matched his fingerprints to a partial handprint on the victim's door, the district attorney's office said.

Patton was convicted in 1999 of rape in Riverside County, according to the district attorney's office.

He faces a mandatory sentence of life in state prison and mandatory lifetime sex offender registration. His sentencing is scheduled for Aug. 24 at the Central Justice Center in Santa Ana.

This story was reported by Times Staff Writer Robert J. Lopez.