An anonymous reader quotes a report from NPR: Having police officers wear little cameras seems to have no discernible impact on citizen complaints or officers' use of force, at least in the nation's capital. That's the conclusion of a study performed as Washington, D.C., rolled out its huge camera program. The city has one of the largest forces in the country, with some 2,600 officers now wearing cameras on their collars or shirts. In the wake of high-profile shootings, many police departments have been rapidly adopting body-worn cameras, despite a dearth of solid research on how the technology can change policing. "We need science, rather than our speculations about it, to try to answer and understand what impacts the cameras are having," says David Yokum, director of the Lab @ DC. His group worked with local police officials to make sure that cameras were handed out in a way that let the researchers carefully compare officers who were randomly assigned to get cameras with those who were not. The study ran from June 2015 to last December. It's to be expected that these cameras might have little impact on the behavior of police officers in Washington, D.C., he says, because this particular force went through about a decade of federal oversight to help improve the department.