It was Humphrey's second attempt to end his life. Humphrey's head was sealed in a plastic bag with pipes running to a car's exhaust pipe and a tank marked "carbon dioxide," Davis said.
Suicide was the likely cause, but nothing has been ruled out, said Mike Downing, an investigator with the Pima County Medical Examiner's Office, where Humphrey's body was taken for an autopsy. "It appears that the suicide was by inhalation by a variety of possible toxic gases," Davis said.
Next to Humphrey, 55, in the tent was a purple shroud, an item found with the cult members whose bodies were discovered March 26 in a mansion in Rancho Santa Fe, a posh San Diego suburb. He was wearing black sweat pants and a black T-shirt with a patch on the sleeve saying, "Heaven's Gate Away Team," Davis said.
Davis said a deputy met Humphrey's daughter at the Flying J Truck Plaza in Ehrenberg on Tuesday. His daughter, who lives in the Los Angeles area, was searching for her father after she received a suicide letter saying he planned to end his life in Ehrenberg.
"She had come to the area hoping that she could find her dad," Davis said. "But it's a large open desert area, and that's when she called us." Two hours later, deputies found Humphrey at a small campsite about two miles southeast of Ehrenberg.
Humphrey served as spokesman for the Away Team, a group of former Heaven's Gate members who staged a public showing of a Videotape by Marshall Herff Applewhite, the cult's leader who perished at the mansion. At the showing in Berkeley, Calif., last August, Humphrey said he was unsure whether anyone could still join his 39 brethren.
"We're not saying that the window of opportunity is closed, but I'm definitely not saying that it's still open," Humphrey said. A note next to Humphrey said, "Do not revive" and had two phone numbers to contact his daughter, Davis said.
Humphrey carried a $5 bill and four quarters, Davis said, similar to the money Heaven's Gate members had on them in the mass suicide. Former cult members said Heaven's Gate members began carrying that amount of money after one was arrested for vagrancy.
Formed by Applewhite in the early 1970s, the Heaven's Gate cult followed a bizarre theology of Christianity and UFOs. The cultists who killed themselves last year left videotaped messages saying they were shedding their bodies - which they called "containers" -for a trip to a "level beyond human" aboard a spaceship trailing the Hale-Bopp comet.
Humphrey was one of three cult members who held a news conference in San Diego a few weeks after the mass suicide in an attempt to explain the group's beliefs. He said he left the group because he had grown impatient. "I left the group because it had been 15 years, because many of the things we were told were going to happen didn't," he said at the news conference. "I got tired of waiting."
However, two months after the mass suicide, Humphrey, of Denver, unsuccessfully attempted suicide in a hotel room a few miles from the Rancho Santa Fe mansion by taking alcohol and phenobarbital. With him was fellow cult member Wayne Cooke of Las Vegas, who died.
Afterward, Humphrey told the 'Contra Costa Times', "I still don't want to be here. I have no plans to go out and do this. However, I also have no plans to stay on this planet until the vehicle dies of old age."
On a page posted on the World Wide Web, Humphrey said he met cult co-founders Applewhite and Bonnie Lou Nettles Trusdale in 1975 and was converted from family man to follower. Trusdale, also known as Ti to Applewhite's Do, died in 1985 of cancer. "Now, according to this world and all of what it measures sanity by, I am definitely, 100 percent just as crazy as those two people," wrote Humphrey, whose cult name is Rkkody, pronounced Rick-o-de.
The doctrines of Heaven's Gate blended science fiction with New Age mysticism, borrowing some terms from the popular 'Star Trek' TV series. The "Away Team," for instance, is a fixture of 'Star Trek' missions.
Longtime friend and former cult member Dick Joslyn of Tampa, Fla., said he wasn't surprised to hear of Humphrey's death. "I knew it was a possibility," Joslyn told the 'North County Times' of Escondido, Calif. "There are a few others out there that are on the borderline. One by one, they could go."
A Phoenix "Arizona Republic" writer Eric Miller contributed to this article.