Police departments with more restrictions reduce citizen fatalities.
The Use of Force Policy Analysis report describes their findings in more detail. "In theory, police departments establish rules regarding the use of force, which include the expectation and power to discipline officers who fail to uphold the department’s standards. Instead, many police departments fail to establish common-sense restrictions on police use of force – including deadly force – that would actually benefit the communities they are supposed to protect and serve. According to our findings, fundamentally changing use of force polices can dramatically reduce the number of people killed by police in America."