Patrons on board the Pittsburg bound train reported that a male suspect was masturbating on board. The reporting party left the train at South San Francisco Station, but the suspect remained on board. Officers intercepted the train at Daly City Station and located the suspect on board. No other victims came forward. Record checks showed that the suspect had an outstanding $30,000 arrest warrant for larceny, held by SFPD. The man was booked at the SF County Jail for his warrant.