(CNN)– Police identified the shooter of two NYPD officers as Ismaaiyl Brinsley.
He arrived in New York from Baltimore, but had a residence in the Atlanta suburb of Union City, Georgia. Bratton said that Brinsley was somehow connected to Brooklyn, but would not discuss that information.
Bratton said at this time, there was no indication Brinsley was connected to any terrorist groups or organized entity.
Police were investigating posts Brinsley allegedly made on social media.
There was at least one post threatening to kill police on an Instagram account in his name. The account also displayed a handgun and a message that said it may be his last post.
Bratton said that the suspect had earlier shot and seriously wounded a woman believed to be his ex-girlfriend in Baltimore.
Brinsley also had a lengthy arrest record in Georgia, mostly involving charges of shoplifting and illegal weapons possession. He was also charged with property damage and obstructing a police officer.
He pleaded guilty to many of the charges, according to police and court records.
Baltimore police received information that Brinsley had made threatening comments about officers, and sent a warning to police in New York, Bratton said.
That message came almost the same time the ambush happened.
U.S. Attorney General Eric Holder called the attack “an unspeakable act of barbarism.”
De Blasio also called the shootings an “assassination.”
“It is an attack on all of us,” he said. “It is an attack on everything we hold dear.”