Around 3 p.m., police say a stolen "blacked out" Infinity pulled up to the family and showed a firearm through an open window. The four to five male Black offenders then demanded the family's property.
The victims handed over their property and the Infinity took off at a high rate of speed, police said.
No injuries were reported.
The case is being investigated by the Oak Brook Police Department. Anyone with information is asked to contact the department at 630-368-8700, or use the police tip line at Police-TipLine@oak-brook.org.
The Neiman Marcus is located at 6 Oakbrook Center.
No further details were immediately available.