“'Wandering officers' are law-enforcement officers fired by one department, sometimes for serious misconduct, who then find work at another agency. Policing experts hold disparate views about the extent and character of the wandering-officer phenomenon. Some insist that wandering officers are everywhere—possibly increasingly so—and that they’re dangerous. Others, however, maintain that critics cherry-pick rare and egregious anecdotes that distort broader realities. In the absence of systematic data, we simply do not know how common wandering officers are or how much of a threat they pose, nor can we know whether and how to address the issue through policy reform."