(Tony Dejak | AP file photo) Demonstrators block Public Square in Cleveland during a protest over the police shooting of 12-year-old Tamir Rice, Nov. 25, 2014. A wave of police killings of young black men in 2014 prompted 24 states to quickly pass some type of law enforcement reform, but many declined to address the most glaring issue: police use of force. Six years later, only about a third of states have passed laws on the question.