Watch What I'm Going to Do': NYPD Reveals Chilling Details of Ismaaiyl Brinsley's Journey to New York

The man accused of fatally shooting two New York City police officers on Saturday — and then taking his own life — had a troubled past and apparently announced his murderous plans just before carrying them out.

In a Sunday afternoon press conference, NYPD Chief of Detectives Robert Boyce sketched out what the police know so far about Ismaaiyl Abdullah Brinsley, the man who gunned down two NYPD officers while they were sitting in their patrol car.

This 2009 booking photo provided by the Springfield, Ohio Police Department shows Ismaaiyl Brinsley after an arrest on a felony robbery charge. Authorities say Brinsley ambushed two New York City police officers in their patrol car in broad daylight Saturday, Dec. 20, 2014, fatally shooting them before killing himself inside a subway station. (AP Photo/Springfield, Ohio Police Department)

Boyce said Brinsley came from a Muslim family, but that police had no evidence he had been radicalized.

In fact, his sisters and mother were all estranged from him, police said, and his mother apparently told police that she had, in the past, been afraid of Brinsley and that he had tried to commit suicide before.

Boyce had at least 19 prior arrests, Boyce said.

On Saturday, Brinsely burst into his 29-year-old ex-girlfriend's apartment in Baltimore and shot her in the stomach.

Police said she had been hospitalized and intubated, but that she was responsive and that police were speaking to her about the shootings.

NYPD Chief of Detectives Robert Boyce addresses the media Sunday afternoon. (Image via NBC News)

After shooting his ex-girlfriend, 28-year-old Brinsley fled to New York City, making several phone calls along the way.

Police have dozens of witnesses and contact points to trace Brinsley's journey, Boyce said, and are actively pursuing more.

Upon arriving in New York, Brinsely apparently approached some strangers and asked them about their gang affiliations and told them to follow him on Instagram — the medium on which he had posted, “I’m putting wings on pigs today. They take 1 of ours, let’s take 2 of theirs,” followed by the hashtags Shootthepolice RIPErivGardner (sic) RIPMikeBrown.

Then he told the strangers, "Watch what I'm going to do," walked up to the squad car containing officers Rafael Ramos and Wenjian Liu — and squeezed off four shots.

He fled the scene but was pursued by witnesses, and later committed suicide in front of at least 10 witnesses, Boyce said.

So far, Boyce said, it did not appear that Brinsley had gang ties or a religious motivation behind the shooting.

This story has been updated.

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