Dead Reckoning — George Douglas

After a large-scale post office robbery, expert peterman Edgar Mulley's fingerprints are found on a safe and he lands in jail. The money has never been recovered, and three years later Mulley makes a successful break for freedom. The North Central Regional Crime Squad lands the case when a "grasser" gets information to them. But before Chief Superintendent Hallam and Inspector "Jack" Spratt can interrogate the informer, he is found dead. Then, a second mysterious death occurs...