The off-duty officer who shot and killed Delrawn Small after they both stopped at a red light in Brooklyn last week was placed on modified duty and stripped of his gun and badge, Commissioner Bill Bratton said Monday.

The officer, Wayne Isaacs, had just finished his shift at the 79th Precinct when he and Small, 37, both stopped for the light just after midnight on July 4.

The incident was first reported as road rage — and police have said that Small apparently punched Isaacs repeatedly before the cop took out his service weapon and fatally shot Small.

But a video that was published over the weekend appeared to show Small walking up to the car and then immediately being struck by a bullet, stumbling back and finally collapsing.

The incident is being investigated by the state attorney general’s office, who has the power to take over any investigation where an officer kills an unarmed civilian per the governor’s executive order.

Bratton said he was briefed on Friday and that the force investigation division is reviewing videos as well as looking for more. They are also looking to find at least two witnesses, including one who was also parked at the red light at the time who “may have witnessed some of the circumstances,” Bratton said.

“We will investigate to the best of our abilities, which are extensive,” he added.