Police have charged an 18-year-old Wahiawa man with 16 counts of sexual assault dating to December 2012.

According to police, Trenton Manner was engaged in a “boyfriend/girlfriend” relationship with a 12-year-old girl that became sexual.

The girl’s mother alerted police on Feb. 12. After two separate interviews, the girl identified Manner in a photographic lineup on March 1.

On Thursday, Manner was located at a Wahiawa address and arrested.

Manner was charged Thursday with nine counts of first-degree sexual assault and seven counts of third-degree sexual assault. His bail has been set at $100,000.