When Ian D. Anderson was pulled over for failing to use a turn signal in June, police asked the 23-year-old why he had three teenage girls in his vehicle at 2:40 a.m.

His answer, according to West Valley City police: He was having sex with one of them.

Investigators say Anderson and a 14-year-old girl had sex June 12 in his truck in the parking lot of Monroe Elementary School, 4450 W. 3100 South, in West Valley City.

Anderson will be arraigned in court Friday . He was charged in 3rd District Court last month with third-degree felony unlawful sexual activity with a minor.

Anderson was headed east on 3500 South early the morning of June 15 when he was stopped, according to a booking statement. The officer noticed the three girls in the vehicle and asked why he was with them. He said he had a sexual relationship with one of the girls, who he thought was 16, and had sex with her days before, the statement said.

While filling out a witness statement, Anderson also said he had sexual pictures of girls on his cell phone, which police verified, according to the statement.

The women in the photos who could be identified were contacted by authorities and all turned out to be older than 18, said Alicia Cook, Salt Lake County District Attorney's Office spokeswoman. No charges were filed based on possession of those photos or other photos showing women whose ages and identifications could not be determined, she said.