On July 6, Nakia Jones, a police officer in Warrensville Heights, Ohio, was awakened by her teenage son bursting into her room, on the verge of tears. “Did you see the shooting?” he asked. The day before, in Baton Rouge, Louisiana, someone had filmed two police officers tackling and then shooting to death a black man named Alton Sterling. The video showed in bloody detail how quickly an officer can take a life at point-blank range. The clip left Jones’s son, a straight-A student and captain of the school band, sad and confused.

“Mom, not only am I afraid of being shot by another black male,” she recalls him saying. “Do I also have to be afraid of somebody who wears the same uniform as you do?”

…

And that’s a very good thing, for the police and the communities they serve. Evidence suggests that diversity can improve the overall department, says David Sklansky, a Stanford Law School professor who first wrote about police demographics a decade ago. Having a more diverse agency can help break down the rigid mentality that often develops among officers and makes it easier to implement reforms. “Fifty years ago, there was one way, basically, to be a police officer, one way to think like a police officer,” he says. “That’s not true anymore.”