four people shot dead on subway train near Chicago suspect in custody four people are dead following a mass shooting aboard a Chicago Transit train Monday morning police said the victims they were all passengers on the train early this morning said Forest Park deputy chief Chris chin a suspect is in custody for the shooting which police believe to be an isolated incident there is no immediate threat and this appears to be an isolated incident on this unfortunate day said chin investigators are working with the Chicago trans authority to review surveillance footage of the shooting surveillance video was instrumental in identifying the suspect who was taken into custody about an hour and a half after this heinous act of violence should never have occurred especially on a public transit train the transit authority said in a statement