Recent polls show a majority of Americans say we need major changes to how police enforce the law and provide public safety. Policymakers and political leaders—under pressure from the Defund and Black Lives Matter movements after high police killings of Black people like Breonna Taylor, George Floyd, and numerous others—are now considering a variety of measures to curb police brutality. But Harvard Kennedy School faculty members Sandra Susan Smith, the Daniel and Florence Guggenheim Professor of Criminal Justice, and Assistant Professor of Public Policy Yanilda González say history has shown that reforming the police is much easier said than done.

In her studies of policing in Latin America, González says authoritarian police forces have been able to block or roll back reforms even in otherwise democratic countries. In countries with high levels of polarization and inequality, including the U.S., she says, police are often given the role of protecting “us”—the dominant group—from “them.” 

Smith, the new director of the Kennedy School’s Program in Criminal Justice Policy and Management, says studies show that many widely-proposed reforms simply have not been effective in reducing police brutality. Measures like anti-bias training, body cameras, and diversity hiring fail, she says, because they put the pressure on individual officers to change deeply-entrenched systemic behavior. 

So if those things won’t work, what will?