Investigators in the US say the gunman who fatally ambushed two police officers in New York had a long criminal record and deep hatred for police.
Officers Raphael Romas and Wenjian Liu were murdered whilst sitting in their patrol car in Brooklyn.
The killer apparently posted anti-police messages on social media before the assassination.
And Chief of Detectives, Robert Boyce says the the gunman spoke to people on the street moments before the shootings:
