To many in law enforcement, speaking out against another cop is a betrayal that can’t go unpunished. Officers who break the blue wall of silence have had dead rats and feces stuck in their lockers. They’ve received death threats, requests for backup ignored, family members threatened and drugs planted on them. USA TODAY spent a year unearthing similar episodes across the country and compiled the most comprehensive public accounting of police retaliation ever compiled. Learn more about the blue wall of silence in the link in our bio.