SAN MATEO, CA (KRON) – San Mateo police have arrested a man for allegedly masturbating and exposing himself in front of a 16-year-old girl on Monday evening, police said.

At around 5:55 p.m., the girl was walking west up the roundabout leading to the Monte Diablo Avenue and Amphlett Boulevard pedestrian overcrossing. That’s when police say she noticed a man masturbating while exposing himself to her.

The girl went home and contacted police.

Officers responded to the area and found the suspect, 35-year-old Cristian Morales. Police then arrested him.

Authorities say Morales is a sex offender.

He was taken to the San Mateo County Jail for the following charges: Indecent Exposure (314 PC) and Annoy or Molest a Child Under 18 with a prior conviction (647.7(c)(1) PC).