An argument over money ended with gunfire at a house near Woodlawn Lake early Saturday.
Police say three suspects knocked on the victim's door in the 100 block of Josephine-Tobin just after 3:30 a.m.
Witnesses say he answered the door and began arguing with the men over money.
Investigators say one of the men then shot the victim in the head and all three left the shooting scene.
EMS took the shooting victim to University Hospital in critical condition.