Surveillance footage apparently showing the New York cop killer moments before he shot dead two police officers has been released by police.
The video appears to show Ismaaiyl Brinsley entering the Atlantic Mall in Brooklyn shortly before he approached a parked squad car and shot officers Wenjian Liu and Rafael Ramos in the head.
Brinsley is reported to have told passers-by to "watch what I'm going to do", moments before the attack on Saturday afternoon.
New York Police have described the killings as an unprovoked "assassination". After killing the officers, he ran inside a subway station and fatally shot himself in the head as responding officers pursued him.
Social media posts attributed to Brinsley appear to suggest the 28-year-old carried out the killings in retaliation for the death of Eric Garner, who was killed in a white New York officer's chokehold.
One Instagram post states: "I'm putting wings on pigs today. They take 1 of ours...let's take 2 of theirs".
Help ID the whereabouts of the male prior to shooting/killing 2 officers on 12/20 between 12-2:30pm.Call #800577TIPS pic.twitter.com/ojfJmP9Ucb
— NYPD NEWS (@NYPDnews) December 22, 2014
Allegations of police brutality in the case of Mr Garner and in the killing of unarmed black teen Michael Brown Ferguson, Missouri in August prompted weeks of nationwide protests.
Decisions by US grand juries to not charge either of the officers involved further escalated tensions.
In New York, police-community relations are said to have plummeted to a level not seen since the 1970s.
On Monday the embattled New York Mayor Bill de Blasio called for a pause in protests to allow the family of the two slain officers to mourn.
"I would ask that any organisations that were planning events or gatherings for politics or protests, that could be for another day," Mr de Blasio said.
"Let's accompany these families on their difficult journey and see them through the funerals. Then debate can begin again."
A funeral for Mr Ramos is due to take place on December 27th. The funeral date for Mr Liu is yet to be announced.
Officers Wenjian Liu (left) and Rafael Ramos (right) | Image: NYPD
Meanwhile, Milwaukee could become a new flashpoint in the escalating tensions after another white officer escaped criminal charges over the death of a black man.
Former Milwaukee police officer Christopher Manney claimed to have shot dead Dontre Hamilton, who was mentally-ill, in self-defence back in April.
He was fired in October for failing to follow police procedure. The US Justice Department is now investigating whether civil rights laws were broken in the case.
