Anecdotal, but it suffices.
So it is in Rialto, Calif., where an entire police force is wearing so-called body-mounted cameras, no bigger than pagers, that record everything that transpires between officers and citizens. In the first year after the cameras' introduction, the use of force by officers declined 60%, and citizen complaints against police fell 88%.
What happens when police wear cameras isn't simply that tamper-proof recording devices provide an objective record of an encounter—though some of the reduction in complaints is apparently because of citizens declining to contest video evidence of their behavior—but a modification of the psychology of everyone involved.
What Happens When Police Officers Wear Body Cameras - WSJ
"The law is reason, free from passion."
I wonder how long it will be until the first privacy violation complaints hit the ACLU.
"I believe in a Spinoza's God who reveals himself in the harmony of all that exists, but not in a God who concerns himself with the fate and actions of human beings."
--Albert Einstein, 1929