Mysterious 911 call: the unsolved case of Jamie Lynn Santos

In October of 1991, 27-year-old Jamie Lynn Santos, who worked as an exotic dancer, was murdered in her home in the Chicago suburb of Wheeling, Illinois. A male caller dialed 911 from a public payphone to report an unconscious woman at Santos's address, asking them to hurry.  The 911 call went to a dispatcher in the wrong town, so she transferred him, and he repeated his message word-for-word to a second dispatcher. He then hung up when questioned further. Jamie was found unconscious but alive on her bedroom floor, with no signs of a break-in. She died later at the hospital. It was determined that she'd been smothered to death, possibly with a pillow. Nearly three decades later the identity of the 911 caller has yet to be discovered, and the case remains unsolved. You can hear audio on this page about the case (you may have to scroll down a bit):

I remember seeing this case on TV (maybe Unsolved Mysteries?), and it drew my interest because I used to have family who lived in that town.