Officers began searching for Myrtle Brown, 73, and Sergio Brown, 35, after family members notified authorities that they could not locate or get in contact with either of them.
As police expanded their search area, Myrtle Brown was discovered unresponsive near a creek behind her home. Her body was transported to the Cook County Medical Examiner's Office.
The coroner says Myrtle's death is a homicide and was caused by multiple injuries from an assault.
Police have not yet been able to locate Sergio Brown.
Brown is a former NFL player who signed with the New England Patriots in 2010 and went on to play with the Colts, Jaguars and Bills until his career ended in 2016.
Maywood police are still investigating, and ask anyone with information about the case or Sergio Brown's whereabouts to contact the Maywood Police Department's anonymous tip line at 708-450-1787.