Time of Predators

Otto Penzler and the Mystery Writers of America Present A Time of Predators by Joe Gores, winner of the Edgar Allan Poe Award for Best First Novel
The gang was restless, just looking for idle fun. They roughed up a man they thought was a homosexual--but their game got out of hand and their victim was blinded.
It was Paula Halstead's bad luck to witness the attack and catch a glimpse of one of the boys. After they got through with her, she killed herself.
The police have no leads and can't find the culprits. Paula's husband hires a private investigator to do what the police haven't been able to-with no success.
Curt Halstead refuses to give up; he will have his vengeance on the men who raped and tortured his wife, even if it means entering into their world of sex, violence, and murder.