Martin Scorsese’s suspense thriller, “Shutter Island,” led the North American box office for a second consecutive weekend on Sunday, fending off strong debuts from the comedy “Cop Out” and horror remake “The Crazies.” Leonardo DiCaprio, who has collaborated previously with Scorsese, stars in the picture as a federal marshal stranded at a prison hospital for the criminally insane off the coast of Massachusetts in 1954.
