The Catholic community is mourning the death of a retired priest, who police say was strangled in a car on the shoulder of I-94 in St. Paul on Thursday.

Thirty-two-year-old Nathan Thomas Wondra is charged with second-degree murder in the death of Father Lawrence Johnson.

RELATED: Man self-reports committing homicide along I-94 in St. Paul

Court documents detail how the retired priest lost his life trying to help his accused killer.

According to a criminal complaint, officers responded to I-94 near Prior Avenue around 12:40 p.m. after Wondra called and said he was having a ‘psychotic break and had choked out’ an elderly man.

Wondra said the man, later identified as Johnson, 76, had not been breathing for about 30 minutes. Wondra told authorities that ‘voices in his head’ told him to kill Johnson ‘to save humanity.’

“On scene, a vehicle occupied by two males was located,” Sgt. Mike Ernster, a St. Paul Police spokesperson, told reporters. “One of those males, an elderly male, who was driving the vehicle, was unconscious and not breathing.”

The complaint says a trooper found a silver Mitsubishi parked on the shoulder with Wondra in the front passenger seat and Johnson in the driver’s seat.

Wondra told police he had been hearing voices and having visions for the past five days.

He noted that Johnson had been taking him to the hospital for a mental health evaluation when he heard voices that told him to kill him.

Police say medics responded and provided aid, but Johnson was pronounced dead at Regions Hospital.

Wondra told investigators that he met Johnson, who was a priest, at Wondra’s workplace about a year ago. He stated they would regularly talk and meet up and referred to Johnson as a father figure.

According to the documents, after attending mass on Thursday morning, Wondra wanted Johnson to drive him to Regions Hospital. Wondra said that he had a weak moment and the “voices in his head told him it was his last chance to save humanity.”

Wondra then asked Johnson to pull to the side of the road, after which the complaint says he strangled Johnson.

According to court records, Wondra said a man parked behind them and approached the passenger side of the car, looked in, stood there for a bit, and then went back to his car and drove away.

Wondra told police he called 911 because it was “the right thing to do” and he wanted to take responsibility for what he had done.

In the criminal complaint, he states the voices stopped after he killed Johnson — and that he told authorities that he knew choking Johnson was wrong but the voices in his head told him Johnson “needed to be a martyr for something bigger.”

Wondra told police he had been fasting to “rid his body of Satan and said it was like there was a demon inside him.”

He also told investigators that it was possible something like this could happen again but said he had not been previously diagnosed with any mental health issues.

“It’s very unusual, it has pieces I haven’t seen in thirty years,” Ernster says.

When Wondra was left alone in the interview room, he was talking about how this saved humanity and said he should have stopped and talked to Johnson, who he called a “good guy.”

Wondra’s father told police he hadn’t noticed any mental health issues or changes in his son’s behavior but did note that Wondra hadn’t been feeling well lately.

Court records do not show any civil commitment of Wondra with regards to mental health.

On Friday, Archbishop of St. Paul and Minneapolis Bernard Hebda sent the following message to clergy members:

“I ask you to join me in praying for the repose of the soul of our brother, Father Larry Johnson. I write to let you know that, based on the information available at this time, our understanding is that law enforcement is investigating his death as a homicide. Please know that you, and the soul of Father Johnson, are in my prayers as we learn more about what happened in the coming days and work through this very tragic and difficult situation together.”

Wondra is now in custody in the Ramsey County Jail.

His next court hearing is scheduled for August 5.