Police said private surveillance cameras captured the killing, just after 10 p.m. Monday, along the 2900 block of Ridge Avenue.
Investigators said the 30-year-old victim had just exited the restaurant when the gunman emerged from a vacant lot. They exchanged words before the gunman opened fire.
The victim was shot in the head and back. Police said he collapsed onto a sidewalk and died at the hospital.
Investigators said the gunman fled back through the vacant lot.
Detectives took a witness in for questioning.
Police have not identified the victim, but say he lives just blocks from the crime scene.