The deadly shooting happened inside Emporium Liquors on Monday night.
The beloved store owner Naveen Singh was shot and killed around 6:45 p.m. after an argument, police said.
On Wednesday, police identified the alleged gunman as 27-year-old Antonio D. Diggines of Calumet City.
Diggines was charged with first-degree murder. He was transferred to Markham for a detention hearing, police said.
At least one person living in the neighborhood heard the gunfire.
"I heard, at least, about five gunshots. When I heard it, I knew it was gunshots," Joann Clark said.
This case is still under investigation by the South Suburban Major Crimes Task Force.