Officers responded to a shooting in the area of Michigan Street and Columbia Avenue at 6:30 p.m.
They determined the shooting stemmed from a road rage incident in the area of Michigan Street and Cline Avenue.
One man was killed in the shooting. He has been identified to the Lake County Coroner's Office as 25-year-old Uriel Arambula.
Three other people were wounded. One victim was flown to a Chicago hospital for treatment and two others were transported to local hospitals.
Police have not said what exactly may have sparked the road rage incident no one is in custody.
Anyone with information about the incident is asked to contact Hammond police at 219-852-2988.