The cycle has become common and familiar. An unarmed Black man or woman is shot or choked to death. The police officers involved in their deaths are often placed on paid administrative leave while an investigation is conducted. Outrage builds among the public while an inquiry into the officers’ behavior goes on for months, sometimes years.

So it was a departure from the norm when Derek Chauvin, the former Minneapolis police officer seen in a video with his knee on George Floyd’s neck, was almost immediately arrested and charged with second-degree murder and second-degree manslaughter. Officers Thomas Lane and J.A. Keung, who helped restrain Floyd, and a fourth officer, Tou Thao, who stood by, were also charged on Wednesday with aiding and abetting murder.

Jack McDevitt, director of Northeastern’s Institute on Race and Justice, said that while Minneapolis Police chief Medaria Arradondo’s firing of Chauvin and the other three officers involved in Floyd’s killing signals an ‘unprecedented’ response, police departments must do more to change the way they operate.