A Brooklyn ​cop accused of fatally shooting a civilian during a road-rage incident is headed to trial.

Wayne Isaac, who has been suspended from the ​NYPD since he allegedly killed Delrawn Small last July, faces 25 years to life in prison if convicted. ​​

It was not yet clear if he’d be seeking a bench or jury trial.

Isaac and his attorney, Stephen Worth, declined to comment as they left court.

“It’s hard, it’s been extremely hard,” mumbled Small’s widow Wenona Hauser-Small following the appearance. “I’m taking it day by day.”

Small’s girlfriend and two young children were in the car when Isaac purportedly opened fire, killing him.

Isaac claims Small attacked him after a car chase, in which Small allegedly followed him several blocks believing the off-duty cop had cut him off.

Surveillance footage obtained exclusively by the Post appears to show Isaac waiting a mere second before firing his gun at Small, who had charged over to his car.

Isaac’s case is the first handled by a special AG prosecutor, after Gov. Andrew Cuomo instituted the new procedure in 2015.

Isaac will return to court for hearings in June.