Police Tuesday were searching for the person who shot and killed a 25-year-old South Carolina man visiting his mother in northwest Atlanta Monday night.

The man, identified by the Fulton County Medical Examiner’s office as Warren Roseberry of Clinton, S.C., was killed in the 300 block of West Lake Avenue, about a half mile south of Donald Lee Hollowell Parkway, police spokesman Sgt. Gregory Lyon said.

The original call came in about 10:20 p.m. Police had been contacted about an argument in a parking lot and told that someone had a weapon, Channel 2 Action News reported. When officers arrived at the location, they found Roseberry.

Police, according to Channel 2, believe the gunman might be at the King Lake Apartments. A SWAT team was sent to that location, the television station reported.

Roseberry’s mother, Brenda Roseberry, told Channel 2 that her son was trying to tell everyone to get along.

“They didn’t have to kill my son,” she said.