Red light - Graham Masterton

On a bloodstained mattress in a grimy flat, a burly man lies dead. A terrified girl kneels over his body. It doesn't take DS Katie Maguire long to identify the murdered victim. He is someone she has been trying to convict for years - a cruel and powerful pimp who terrorised girls who worked for him. It's Katie's job to catch the killer. But with men like this dead, the city is safer. When a second pimp is horrifically murdered, Katie must decide. Should she do her job, or follow her conscience? Should she allow the killer to strike again?