File- This Feb. 2, 2016, file photo shows New York City Police Commissioner William Bratton listening while testifying on Capitol Hill in Washington before the Senate Homeland Security and Government Affairs Committee hearing on the frontline response to terrorism.   Bratton is resigning his post atop the nation's largest police force. Mayor Bill de Blasio announced Tuesday, Aug. 2, 2016, that Bratton will retire next month, and that James O'Neill, the department's top chief, will succeed him. Bratton had said last month that he would not remain head of the NYPD past the end of de Blasio's first term in 2017. (AP Photo/Cliff Owen, File)