New York police commissioner Bill Bratton ( C) speaks as New York City Mayor Bill de Blasio and other NYPD officials look on at a news conference at WoodHull Hospital about the two New York Police officers who were shot dead in the Brooklyn borough of New York, December 20, 2014. A gunman who had posted anti-police statements on social media ambushed and fatally shot two New York police officers as they sat in their squad car on Saturday and then killed himself, police said. [Photo/Agencies]