Investigators want to talk with anyone who might have known the man, identified as 36-year-old Allen Walker.
Walker's frozen body was found Wednesday near a makeshift tent between the Metra Tracks and the Fox River.
Police say they're treating the incident as a homicide.
Viewers with disabilities can get assistance accessing this station's FCC Public Inspection File by contacting the station with the information listed below. Questions or concerns relating to the accessibility of the FCC's online public file system should be directed to the FCC at 888-225-5322, 888-835-5322 (TTY), or email@example.com.