An off-duty Newark police officer was arrested early Monday after fatally shooting his estranged wife and seriously wounded her boyfriend before fleeing, officials said.

Acting Lt. John Formisano, 49, a 24-year veteran of the department, was accused of shooting the woman inside a home on Mirror Place in Jefferson around 11:20 p.m. Sunday, according to a Newark police spokeswoman.

He left two children unharmed in the house, Morris County Prosecutor’s Office spokesman Peter DiGennaro told The Post. Their names, ages and relationship to Formisano were not released.

The names of the woman and the boyfriend, who was listed in critical condition, also were unavailable.

Formisano was arrested during a motor vehicle stop around 1:30 a.m. Monday on Foxcroft Drive in Livingston, where his parents live about 30 miles from the crime scene, according to the Daily Record.

Police said there was no danger to the public.

Formisano was suspended from duty without pay after the shooting, but was not immediately charged, according to reports and officials.

Public records show Formisano bought the home on Mirror Place almost a decade ago.

Formisano’s arrest shocked his colleagues on the Newark police force, James Stewart Jr., president of the Newark Fraternal Order of Police, told NJ.com.

“To say that we are all shocked by the events of early this morning would be a tremendous understatement,” Stewart said in a statement, adding that he attended the police academy with Formisano.

“He had been going through marital problems and he has been taking care of his mother who is battling serious health issues, but there was no indication that any violence was being contemplated,” Stewart said.

“Our hearts break for his children and our condolences go out to the shattered family of his wife, we are all just stunned,” he added.

Thomas Verrone , a retired Passaic County sheriff’s deputy who lives in the neighborhood, said that one of his two daughters heard gunshots.

“She heard the shots but she thought it was fireworks because kids run around doing that,” he told the news outlet.