Night Watch (Unabridged‪)‬

A young woman lies dead, strangled by a killer still prowling the sweltering, run-down neighborhood. The young wife of a police lieutenant receives threatening phone calls; the precinct's patrol cars are sabotaged; even the puppies the officers have adopted as mascots are savagely slain.

It looks like there's a psycho on the loose with a vendetta against the cops. And then the widow of a precinct cop is found horribly murdered. The signature of the first crime is on this one. But a deadly new element has been added - another murderer is imitating the first one's methods.