What to Know A 37-year-old man was shot and killed by an off-duty NYPD officer in East New York, Brooklyn early Monday morning

A traffic dispute led up to the confrontation. Others have reported the man punched the cop repeatedly but video appears to contradict that

The state attorney general is reviewing the video as part of its investigation

Newly emerged surveillance video shows the moment an off-duty NYPD officer shot and killed an unarmed motorist who approached his vehicle after an apparent traffic dispute in Brooklyn earlier in the week.

The video obtained by The New York Post shows Delrawn Small approaching the vehicle of Officer Wayne Isaacs as they were stopped at the intersection of Atlantic Avenue and Bradford Street.

Small walks across two lanes of traffic to get to Isaac's driver-side window, and one second later is seen staggering backward and collapsing, video shows

Isaacs' car lurches forward a few feet before he slams on the brakes and gets out. He appears to tuck the gun back into his waistband as he walks over toward Smalls, briefly surveys him, then walks back into his car. Officials have said he called 911 and waited there until patrol officers arrived.

Other pedestrians hurry past, apparently frightened, the video shows. Vehicles also drive past. Moments later, Small's girlfriend frantically runs toward the scene. That's where the footage cuts off.

Issacs was placed on administrative leave pending the outcome of the investigation, police said.

Police said the incident unfolded shortly after Isaacs ended his shift at a Brooklyn precinct and drove away in his civilian clothes. It wasn't unusual that he was armed: The NYPD allows off-duty officers to carry weapons and to take police action if they encounter criminal activity.

Police say the girlfriend who was riding with Small and their two children, ages 5 months and 14 years, told investigators that he became enraged after he thought the officer cut him off, then followed the officer's car to the stoplight despite her pleas to calm down and let it go. They say there was no was back and forth that would have made Isaacs aware that he was being pursued or that Small knew he was an officer.

The video obtained by the Post corroborates a law enforcement official's account of the video to The Associated Press earlier this week. The official who viewed the video told the AP that it showed Small walking around the front of the officer's car and leaning through the driver's window.

Small then "nearly instantaneously" stumbles back and ends up collapsing behind the officer's vehicle as it lurches forward, the official said.

The tape contradicts a prior New York Post report quoting a man claiming he saw Isaacs get out of his car and shoot Small. Investigators believe Small had punched Isaacs with the officer still seated behind the wheel before the officer fired three times, leaving behind shell cases found inside the car.

The video has emerged as key evidence in a review by the NYPD and the state attorney general's office into the shooting.