An officer responded to the station regarding a male acting erratic, and eventually located him on the platform. During the contact, the subject attempted to jump onto the track way but was physically restrained by the officer. The officer, with the help of a civilian BART employee, then managed place the subject in handcuffs without further incident. The subject, who also made suicidal statements, was transported to the county hospital for a psychiatric evaluation. A sergeant responded to perform the use of force investigation. The officer and the subject were not injured.