The Midnight Murders

The date is the 16th October 1924.
Every night for 3 nights at 12 midnight, the New York Police Department have received a call reporting a dead body. Each time the caller has been the same person, and has declared their guilt openly, but each time, when the police arrived on the scene, the caller had vanished, nothing but a brutally murdered body left behind. With no leads, no evidence and no way of knowing where the killer will strike next, the police are forced to turn to renowned private detective George Knight, in the hope that he can track down the killer before more lives are lost.