Lansing police said officers responded to 17625 Torrence Avenue for a report of shots fired around 1:45 p.m. Saturday.
There, officers found 66-year-old Victoria L. Olson, of Thornton. Olson, who had suffered multiple gunshot wounds, was pronounced dead at a local hospital, police said.
What led up to the shooting was not immediately clear.
The Lake County Coroner's Office ruled Olson's death a homicide, and police gathered evidence and witness statements.
Police said Adebowale A. Oyelekan, a 40-year-old Lansing man, has been charged with first-degree murder.
Oyelekan is expected to appear in court in Markham.
Police did not immediately provide further information.