The Walton case is singular in that the victim vanished for days on end with police squads out searching.
Crew took polygraph examinations administered by Cy Gilson, an Arizona Department of Public Safety employee. His questions asked if any of the men caused harm to Walton (or knew who had caused Walton harm), if they knew where Walton's body was buried, and if they told the truth about seeing a UFO. The men all denied harming Walton (or knowing who had harmed him), denied knowing where his body was, and insisted they had indeed seen a UFO.
Gilson concluded that all the men were truthful, and the exam results were conclusive. Clark quotes from Gilson's official report: "These polygraph examinations prove that these five men did see some object they believed to be a UFO, and that Travis Walton was not injured or murdered by any of these men on that Wednesday". If the UFO was fake, Gilson thought, "five of these men had no prior knowledge of it"
Following the polygraph tests, Sheriff Gillespie announced that he accepted the UFO story, saying "There's no doubt they're telling the truth."