A female victim reported that she was on a train on platform #3 and that a male suspect was showing her his genitals. The suspect was described as a white male in his 20's, bald, wearing a black Giants baseball jacket, blue jeans and black shoes. The suspect left the station in an unknown direction. Responding officers were unable to locate the suspect at the station or in the area. The suspect description was provided to Millbrae PD.