An anonymous reader writes:A study from Cambridge University documents an immense drop in complaints against police officers when their departments began using body cameras. But even more surprising is that the data suggests everyone is on their best behavior whether the cameras are present or not. The data was collected in seven police departments, and represents over 1.4 million hours logged by 1,847 officers in 2014 and 2015; the researchers published their data last week in the journal Criminal Justice and Behavior. Officers were randomly assigned to wear or not wear cameras week by week (about half would be wearing them any given week), and had to keep them on during all encounters. The authors used complaints against police as a metric because they're easy to measure, an established practice in most police forces and give a good ballpark of the frequency of problematic behavior. In the year before the study, 1,539 complaints in total were filed against officers; at the end of the body camera experiment, the year had only yielded 113 complaints.