NEW YORK (AP) ― The two New York City police officers who were ambushed and shot to death in their vehicle on Saturday were “quite simply, assassinated,” and the suspect had made Instagram posts that were very antipolice, the police commissioner said.

William Bratton said the officers, Liu Wenjin and Raphael Ramos, were shot without warning or provocation. The suspect then ran inside a subway station and fatally shot himself in the head.

Bratton said the suspect shot his ex-girlfriend earlier Saturday in Baltimore and made posts from her Instagram account.

Authorities did not get into the specifics of the contents of the posts, but two officials told the Associated Press that he posted about shooting two “pigs” in retaliation for the death of Eric Garner.

They spoke on condition of anonymity because they were not authorized to speak publicly.

Police in New York are being criticized for their tactics following the recent chokehold death of Garner, an unarmed black man who was stopped by police on suspicion of selling loose, untaxed cigarettes. Amateur video captured an officer wrapping his arm around Garner’s neck and wrestling him to the ground. Garner was heard gasping, “I can’t breathe” before he lost consciousness.

The last shooting death of a New York Police Department officer came in December 2011, after a report of a break-in at a Brooklyn apartment.