In response to the high rate at which American police kill civilians, many on the left have taken up the call for defunding the police, or abolishing the police entirely. But some policing experts are instead emphasizing a different approach that they say could reduce police killings: training officers better, longer, and on different subjects. “We have one of the worst police-training academies in comparison to other democratic countries,” Maria Haberfeld, a police-science professor at John Jay College, told me.

Police in the United States receive less initial training than their counterparts in other rich countries—about five months in a classroom and another three or so months in the field, on average. Many European nations, meanwhile, have something more akin to police universities, which can take three or four years to complete. European countries also have national standards for various elements of a police officer’s job—such as how to search a car and when to use a baton. The U.S. does not.

The 18,000 police departments in the U.S. each have their own rules and requirements. But although police reform is a […]