CRYSTAL LAKE, Ill. — Police have released a recording of the 911 call a suburban Chicago man made when he discovered his 5-year-old son was missing.

In the call made last Thursday, Andrew Freund Sr. tells a dispatcher that he arrived home from a doctor’s appointment to discover his son, Andrew “AJ” Freund, is gone. He says he searched the Crystal Lake house, garage, a park, and other locations but can’t find him. Police released the recording Tuesday.

Crystal Lake police meanwhile announced they are still searching a nearby park and using sonar equipment to search ponds in the area. Police have asked neighbors for surveillance video in the hunt for clues about the boy’s disappearance.

Police say they boy’s mother, JoAnn Cunningham, is refusing to cooperate with detectives.