A man has been arrested for allegedly exposing himself to school-aged girls in Carmel Valley over the last decade, police said Wednesday.

Investigators said that, beginning in 2015, the man allegedly pulled his car alongside girls as they walked home, San Diego police Detective Michael Weaver said. The man would then open his passenger side door, expose his genitals and begin masterbating, investigators said.

The man was generally reported sitting in a white Toyota sedan or a silver Buick SUV, Weaver said.

Police said 17 girls were targeted over nearly 10 years. They were identified as students at Torrey Pines High School, Carmel Valley Middle School or Solana Pacific Elementary School, with the most recent incident in May.

Officers said they had had trouble pinpointing and identifying the suspect until the most recently reported occurrence.

“A high school victim had the courage to turn around and use her cellphone and took a photo of the suspects car, and thats how we identify him,” Lt. Paul Yang said.

The man, identified as Rene Cruz, 27, of Carmel Valley, was arrested Monday on a warrant and pleaded not guilty Wednesday to 24 counts of indecent exposure, officials from the City Attorney’s Office said.

Cruz was released after posting bail, officials said. He will be monitored by a GPS tracking device and was ordered by a judge to stay 100 yards away from all schools in the county, officials said. He must also have no contact with minors.

“For years, Cruz fixated on unsuspecting young girls leaving school for the day, seized their attention, and then exposed them to lewd conduct as they walked by,” City Attorney Mara Elliott said in a news release. “We believe there may be other victims since Cruz’s conduct occurred over a long period at numerous school sites.”

Investigators asked anyone who believes they may have been a victim to contact the police department’s Northwestern Division investigations unit at MWeaver@pd.sandiego.gov.