Walker was last seen in Sioux Falls, South Dakota on September 20, 2010. His van, which he lived in, was later found abandoned at Falls Park. He has never been heard from again. Walker is a transient and had no known medical conditions at the time of his disappearance, although he did use a cane to walk. Since he went missing there have been numerous reported sightings of him in the area, but none have been confirmed. His case remains open and unsolved.