The Midnight Man plot
"The Ex-con. The Hippie. The Senator. The Pervert. The Lesbian. The Professor. The Sheriff. The Sadist. One of them is a murderer. All of them make the most fascinating murder mystery in years."
Jim Slade is an ex-cop. He is found guilty of murdering the man who had a relationship with his wife and is sent to prison. After his release, his probation officer helps him get a job as a night watchman at a university. On one of his nightly rounds, he finds the body of a student. The police soon spot a suspect. Slade, however, does not believe the theory of the police and starts an investigation himself.