A patron on board the Pittsburg bound train reported that she saw a male suspect, with what she believed to be the magazine of a handgun protruding from his shirt. The suspect, who boarded the train at Powell Street Station, was described as a black male in his 20's, 6 fee tall, with a dark complexion, wearing a light blue denim jacket, white shirt, and light colored jeans. The suspect was last seen walking toward the front of the train. Officers responded to West Oakland Station and searched the train. A male matching the suspect description was located on the third car from the lead and was detained without incident. The reporting party identified the man as the one she had seen at Powell Street. The man was searched, but no weapon or contraband was located. The train was released after about a 12 minute delay.