Police departments across the nation are implementing policies that would require officers to intervene when fellow officers use excessive force. Minneapolis has such a policy, yet it was not enough to spur Derek Chauvin’s colleagues to intercede to save George Floyd’s life.

Our years of studying constitutional civil rights have taught us that police policies and even criminal statutes are not enough to overcome the “blue wall of silence” among officers. What’s needed are state laws that create an affirmative duty for bystander cops to intervene to prevent use of excessive force or other civil rights deprivations, and that allow civil suits against cops who don’t.