Came across this article by the Serpico in Politico in 2014. Makes fascinating reading in light of current events.
[A]n even more serious problem — police violence — has probably grown worse [than it was when Serpico was in the NYPD in the early 1970s], and it’s out of control for the same reason that graft once was: a lack of accountability.
. . .
Today the combination of an excess of deadly force and near-total lack of accountability is more dangerous than ever: Most cops today can pull out their weapons and fire without fear that anything will happen to them, even if they shoot someone wrongfully. All a police officer has to say is that he believes his life was in danger, and he’s typically absolved. What do you think that does to their psychology as they patrol the streets—this sense of invulnerability? The famous old saying still applies: Power corrupts, and absolute power corrupts absolutely.
. . .
And with all due respect to today’s police officers doing their jobs, they don’t need all that stuff anyway. When I was [a] cop I disarmed a man with three guns who had just killed someone. I was off duty and all I had was my snub-nose Smith & Wesson. I fired a warning shot, the guy ran off and I chased him down. Some police forces still maintain a high threshold for violence: I remember talking with a member of the Italian carabinieri, who are known for being very heavily armed. He took out his Beretta and showed me that it didn’t even have a magazine inside. “You know, I got to be careful,” he said. “Before I shoot somebody unjustifiably, I’m better off shooting myself.” They have standards.
Frank Serpico, The Police Are Still Out of Control, POLITICO Magazine, Oct. 2014.