Christy E. Lopez is a professor at Georgetown Law School and co-director of the school’s Innovative Policing Program.

Even as we demand accountability for the officer accused of killing George Floyd, we should be equally focused on preventing needless police killings in the future. One of the most important preventive steps we can take is to create a culture in which police officers themselves step in to prevent abuse, and are supported when they do.

The video of Floyd’s killing underscores with terrible clarity why we need a police culture of peer intervention. Imagine if any of the officers on the scene in Minneapolis had asked — or told — Officer Derek Chauvin to take his knee off Floyd’s neck, or had provided Floyd with medical assistance. Floyd might well still be alive.

Immediate officer intervention also can be far more effective in preserving and restoring police legitimacy than any after-the-fact apology or even prosecution. If one of the other officers at the scene, instead of standing by and ignoring public pleas for help, had moved Chauvin away from Floyd and started providing medical care, the public reaction might have been quite different, even if Floyd had died.

Through his actions, the intervening officer would have communicated: “This is not who we are. This is not who I am. That is one officer. The rest of us are not that officer.” Instead, the message was: “We are the police. This is what we do.”

Such intervention is not only good for the public, it is in the best interests of police. If the officers in this situation had intervened, they might still have their jobs.

Progressive police agencies and reform advocates have long recognized the importance of officer intervention. Indeed, police have a legal “duty to intervene,” and the Minneapolis Police Department changed its force policy in 2016 to require officers to intervene if they witness another officer using excessive force. The Minnesota attorney general’s Working Group Report on Police-Involved Deadly Force Encounters, released this year, similarly recommended that all law enforcement officers in Minnesota be required to intervene to prevent unreasonable force.

But as Floyd’s death underscores, peer intervention, like any worthwhile anti-bullying program, must be more than a requirement in a policy manual; otherwise, it’s not likely to be effective. Social science tells us that intervening to prevent wrongdoing in the middle of a tense incident is far more difficult than we recognize. Notwithstanding the legal duty, there are inhibitors to intervention that most officers will be unable to overcome in the moment unless they have been prepared in advance.

This is why, when I worked in the Justice Department’s Civil Rights Division, we included a requirement that officers receive peer-intervention training in many of our police consent decrees with police departments with patterns of using excessive force. And this is why the New Orleans Police Department implemented a robust police peer-intervention program known as EPIC — Ethical Policing Is Courageous — based on the studies of mass violence and genocide by Holocaust survivor Ervin Staub.

It is difficult to assess exactly how much of an impact a program such as EPIC has. After all, if it works, nothing happens: no abuse, no injury, no video, no controversy. But officers in New Orleans and elsewhere report using EPIC training at key moments to keep themselves or others from crossing the line.

In Washington, where I co-lead Georgetown Law’s Innovative Policing Program, we conduct EPIC workshops for our Police for Tomorrow Fellows, a group of Metropolitan Police Department officers and employees selected for their openness to thinking differently about policing. The D.C. police recently began to provide active bystandership training to all officers and recruits. The department has even incorporated intervention principles into its scenario-based academy training — requiring new recruits to identify and intervene when a sergeant is about to violate someone’s rights.

Of course, creating a police culture of peer intervention requires more than training. It requires agency reinforcement at every level, and accountability for officers who fail to intervene when they clearly should have — as, again, the video of Floyd’s death depicts.

There are nearly 18,000 law enforcement agencies employing more than 1 million sworn law enforcement officers in the United States. Each one of those officers needs to meet state-mandated training requirements to be certified by their state. Each state should require peer-intervention training for every officer to meet these certification requirements. And every community should demand that the law enforcement agencies sworn to protect them do so by creating and supporting a culture of peer intervention.

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