Daugherty was killed by a robber at his front door, who also took money from his wife. Her 911 call was released Wednesday.
"He's got a big knife," she tells the dispatcher. The operator then asks Daugherty's wife where she is, and she says she is in her bedroom.
Investigators strongly believe there are people who may know the killer or who the killer is, based on a composite sketch.
Anyone with information should call Schaumburg police.