CNN Anderson Cooper 360 December 23, 2014 04:23:00
Knoll leader was a new york city cop for 20 years. >> i've never seen hostilities this heightened before my career. >> reporter: the patrolman's benevolent association has been withering in its attacks on de blasio. >> there's blood on many hands tonight. that blood on the hands starts on the steps of city hall in the office of the mayor. >> reporter: he and his organization representing beat cops blame the mayor for the way he's handled recent protests. the lack of indictment of police in the killing of michael brown in ferguson, missouri first set off angry protests here. >> what do we want?...