have highlighted mounting tensions between police union officials and the mayor whom they accuse of putting officers' lives at risk with his support for recent protests, involving the eric garner choke hold death and the police shooting of michael brown. >>. >> they tried to tear down when new york city police officers did every day. we tried to warn. it must not go on. it cannot be tolerated. that's blood on the hands starts on the steps of city hall in the office of a mayor. in an apparent show of defiance, police officers gathered at the hospital where the explain officers were taken, and they turned their back on the mayor as he entered for saturday's press conference. >> alexander field joins me live for a growing memorial. a vigil will be held later tonight as we nantd it.