Police said the shooting happened in the 400-block of West Lake Street in Maywood Tuesday night at about 7:30 p.m. When officers arrived on scene they found the victim, identified as 33-year-old Arthur Walton, and his brother with gunshot wounds.
Walton was shot multiple times, police said. His brother was shot in the leg. Walton, who lived in Maywood, was pronounced dead at 7:48 p.m. at Loyola University Medical Center in Maywood.
Family members said Walton was involved in an argument outside the building where the shooting happened, which continued into the building, upstairs to the hall outside the apartment where the victim lived.
No charges have yet been filed against the off-duty officer, and Melrose Park police said the officer has been placed on administrative leave.
Anyone with information about the shooting is asked to call the Maywood Police Department Investigations Unit at 708-450-4471 ext. 4307 or submit an anonymous tip at 708-450-1787.
The Sun-Times Media Wire contributed to this report