NEW YORK, NY - DECEMBER 04:  New York City Mayor Bill de Blasio speaks at a press conference after witnessing police being retrained with new guidelines at the Police Academy  on December 4, 2014 in the College Point neighborhood of the Queens borough of in New York City. The new police guidelines come on the heels of numerous national incidences where white police officers have killed black men.  (Photo by Andrew Burton/Getty Images)