Atlanta police are investigating the shooting death of a man found lying on a sidewalk Thursday afternoon in about the 800 block of Hill Street on the city's southeast side.

About 4:15 p.m., "witnesses called police saying they heard a shot," said Lt. Paul Guerrucci, commander of the APD Homicide Unit. "We located the victim in his early 50s, shot -- it appeared to be once in the chest -- and dead on the scene."

The man's name was withheld pending notification of next of kin. Police did not have a motive for the shooting.

Investigators were canvassing the Grant Park neighborhood Thursday night, "talking to people who are providing some degree of information we can work with," Guerrucci said.

Anyone with information was asked to call Atlanta Crime Stoppers at 404-577-8477 or text CSA Tip to 274637.