CHICAGO (CBS) — A man was shot and killed while trying to protect his girlfriend, when someone tried to steal their car late Sunday night in Logan Square.

Alexis Andrade, 22, was sitting in his car listening to music with his 21-year-old girlfriend across the street from her house on the 3000 block of North Kimball Avenue around 11:45 p.m., when a man walked up to them and demanded their vehicle.

Andrade and the carjacker began fighting, and then the robber shot the 22-year-old man in the chest, arm, and forehead. The victim was taken to Advocate Illinois Masonic Medical Center, where he was pronounced dead.

The woman was not injured. Her sister said she was home when she heard the commotion outside. She saw police, but couldn’t really see what was going on, and had no idea something happened to Andrade and her sister.

“I think he was trying to protect my sister, and then they started fighting. He didn’t know he had a gun, and I don’t know, he shot him,” Daniela Raco said.

Raco said Andrade and her sister had been together for years.

”He was amazing. He was great. He was sweet, nice,” she said. “She was always, ‘Oh my God, he’s the one, I love him.’”

The gunman fled the scene in a dark-colored van with tinted windows. Police had only a vague description of the shooter.

No one was in custody Monday morning.

Area North detectives were investigating.

Police said investigators were reviewing surveillance cameras in the area, to see if there is any video of the shooting or the gunman.