Raymond B. answered 12/03/20
Math, microeconomics or criminal justice
police academies are run like basic training in the military. Police have military ranks like Sergeant, Lieutenant and even General. Police recruit from former military soldiers.
It's no surprise the police then often treat citizens as if they were enemy combatants.
Increase the pay scale for police and you'd get more qualified people applying. The officers with more education tend to less involved in excessive use of force or police shootings.
One aspect of police culture is they don't "rat" on each other. They also don't like to interfere with what another officer is doing, even if it's involving excessive use of force.