An off-duty New York City correction officer accused of fatally shooting a Bronx teenager has been indicted on murder and manslaughter charges, officials announced Monday.

Dion Middleton, 45, allegedly fired at 18-year-old Raymond Chaluisant while the teen was sitting in the passenger seat of an Acura near the Cross Bronx Expressway and Morris Avenue on July 21.

An attorney for Middleton previously said the jail guard acted out of fear for his life after he felt a “stinging in his back” and saw a passenger in the car making a hand gesture.

Chaluisant, who was shot in the face, had an Orbeez water-pellet gun on him, police have said.

Middleton pleaded not guilty to second-degree murder and first and second-degree manslaughter charges during his arraignment on the indictment in Bronx Supreme Court Monday.

He faces up to 25 years to life in prison if convicted of murder, according to Attorney General Letitia James’ office, which is prosecuting the case.

Justice Denis Boyle continued the prior bail conditions set at $1 million bond or $500,000 cash or credit card. He added that Middleton must wear an ankle monitor if he does make bail, the AG’s office said.

Attorney Joey Jackson has claimed that Middleton opened fire in self-defense.

“Let’s call it what it is, a weapon. It looks real and it’s a weapon that shoots pellets which tend to hurt,” Jackson said of the water-pellet gun during a court hearing last month.

AG prosecutor Justin Siebel, responded at the time that Middleton had admitted that he didn’t see anyone holding a firearm and hadn’t heard shots fired.

“His actions show that he does not intend to and definitely did not intend to at the time take any responsibility for the fact that he had just fired a round,” Siebel said at the time.

Jackson did not immediately return a request for comment Monday.