Patrons reported that three male suspects were battering a male victim on the platform. The suspects boarded a Millbrae train, while the victim remained on the platform. Officers intercepted the train at Orinda Station and located three suspects who matched the description given by witnesses. A check of Lafayette Station by another officer revealed that the victim and witnesses had left the area. Record checks of one of the detainees at Orinda revealed that he had an outstanding, no-bail arrest warrant for DUI, held by the Contra Costa County Sheriff's Department. Two of the suspects were released and the suspect with the warrant was booked at the Martinez Detention Facility.