A gunman has shot dead two New York police officers in an ambush, as they sat in their patrol car in Brooklyn.
The suspect then ran inside a subway station and took his own life.
He'd earlier shot and wounded his ex-girlfriend in the city of Baltimore.
Police chiefs say the killer had posted anti-police comments on a social media site.
The murders follow weeks of tension in New York and other U.S. cities over the decision NOT to prosecute white police officers for the deaths of African American men.
New York Mayor Bill de Blasio has condemned the attacks:
