CHICAGO (CBS) — An off-duty Chicago police officer shot and killed his son during a domestic dispute early Wednesday in the Garfield Ridge neighborhood, sources said.

Sources said the off-duty officer was involved in a physical altercation with his son around 1:45 a.m. at a home in the 5600 block of South Nottingham Avenue when he fired his weapon, killing his 23-year-old son.

The Cook County Medical Examiner’s office identified the officer’s son as Rafael Flores. He died at the scene.

Police said Area One detectives are investigating and the incident is domestic-related.

As CBS 2’s Suzanne Le Mignot reported, an ambulance was seen parked outside the house as officers entered. Crime scene tape was also seen in front of the house. Officers were at the scene for more than five hours Wednesday morning.

“We were woken up by the emergency vehicles approaching,” said Jeff Jestadt, who lives two houses down from where the shooting happened.

Jestadt said, while he didn’t hear any gunshots overnight, the large police presence kept him awake.

He has known Flores and his family for about 13 years.

“I consider them to be great neighbors. They’re the kind of people that you know, has your back,” he said. “They were very, very, very nice people. We have the same kind of a dog and that’s kind of our connection between the two of us, two families. Just very nice people overall.”

Jefstadt’s son played baseball with Flores in elementary school.

Of Flores, Jestadt said: “He was just a quiet kid. We’d see him, just over this past summer. He’d go out for walks, by himself. Sometimes he’d take his dog with him. We’d see him out in the alley, sometimes playing basketball or whatever, kind of hanging out. We’d wave. He’d wave back.”

A source said Flores was recently hired as an assistant football coach at St. Rita of Cascia High School. He also graduated from the school in 2015.

The St. Rita Mustangs mourned Flores’ death in a tweet on Wednesday.

Jefstadt said the officer lives at the Nottingham Avenue home with his wife and wasn’t sure if their son still lived with them.

Sources said the off-duty officer was taken to a hospital to be treated for a head injury after the incident.

“I feel horrible for the family,” Jefstadt said.

He added that his heart “absolutely, 100 percent” goes out to the family.

“And I don’t know if they’d ever see this, but we’re willing to do anything we can to help them,” Jefstadt said.

The officer has been on the force for 19 years. The Civilian Office of Police Accountability and the Chicago Police Internal Affairs Division are investigating the shooting.

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