EL CAJON, Calif. -- A former swim coach at El Capitan High School pleaded guilty Monday to molesting a 16-year-old female student at a private residence.

Ryan Campbell Stevens, 22, faces up to three years in prison when sentenced July 6 by Judge Peter Deddeh.

The defendant pleaded guilty to a single charge of oral copulation with a minor.

Stevens, who was a part-time swim instructor at El Capitan last winter and spring, surrendered at the Santee sheriff's substation last Nov. 4, San Diego County sheriff's Sgt. Justin White said.

Stevens allegedly molested the girl three days earlier, as they were taking down decorations at a Lakeside home where a private Halloween haunted house had been staged, according to White.

The girl reported the alleged assault the following day, the sergeant said.

Although the alleged molestation did not occur at El Capitan or at a campus-sponsored function, school officials notified county Child Protective Services, according to Catherine Martin of the Grossmont Union High School District.

Stevens served as a "walk-on'' coach at the Lakeside campus from February to May of last year and is no longer a district employee, Martin said.