A former high school wrestling coach has been found guilty of having sex with a 15-year-old student.

Richard Portugal Ortiz was convicted Wednesday on four of seven counts of sexual conduct with a minor.

Ortiz, 55, was accused of having sexual relations with the girl on numerous occasions. He had been the wrestling coach at Tucson High School, where the girl was a student and member of the wrestling team.

The Arizona Daily Star has not identified the teenage victim, who is minor.

At trial, defense attorney Joseph P. St. Louis tried to cast doubt on the victim’s testimony, noting she had difficulty remembering the dates the incidents occurred.

St. Louis also downplayed the accusations, alluding to possible improper behavior on Ortiz’s part but saying his client ended the relationship when his conscience took hold.

The relationship between Ortiz and the victim was discovered in June 2012 when sheriff’s deputies found the two partially undressed in the back of Ortiz’s van parked on a secluded residential street on Tucson’s far southwest side.

Deputy Pima County attorneys Michelle Chamblee and Dawn Aspacher relied on the victim’s statements and DNA evidence to build their case against Ortiz.

Ortiz is scheduled for sentencing before Pima County Superior Court Judge Javier Chon-Lopez on Aug. 18.

Contact reporter Patrick McNamara at 573-4241 or pmcnamara@azstarnet.com. On Twitter @pm929