Another school suggested that Madalyn, like an ancient ailing mastodon, had slipped off into the deepest jungle for a private death and cremation.
In 1986, O'Hair had discussed her own death in an article in American Atheist magazine and outlined her fear of posthumous revenge by her religious enemies.
"I represent atheism to the world. Wouldn't the religionists love to get their filthy paws on my corpse? And so, I have told Jon and Robin, 'no funeral parlors or mortuaries,'" she wrote.
"What I don't want is for the religious to get the satisfaction of corpse mutilation or activities that would encourage them to assume that they have wrought revenge for their god...I don't want any damned Christer praying over my body or even putting his hands on it," she wrote.
But after one year, there was no proof that Madalyn was alive or dead. There was no proof of anything. But for a strange episode in San Antonio during September 1995, the disappearance of America's most famous atheist might easily have become just another surefire gag line for Conan, Jay, and Dave. Eventually, Madalyn could have joined Judge Crater, Teamster boss Jimmy Hoffa, and aviator Amelia Earhart in the book of unsolved American celebrity disappearances.
But because of one event, the O'Hair chapter is not yet ready to be written.
It began with an advertisement in the San Antonio Express-News on September 3, 1995, for a bargain-priced Mercedes. The classified ad appeared just days after the O'Hair family had left Austin for San Antonio.
It read: "88 Benz 300 SEL, $15,000 cash. Firm. 512-461-4478."
The number was for Jon Murray's cell phone, and when San Antonio real estate agent Mark Sparrow called, a man who identified himself as Jon answered.
He said the car, priced $5,000 under market, could be seen at the Warren Inn, a 300-unit complex of low-rent efficiency apartments on Fredericksburg Road in northwest San Antonio.
Jon said that he could be found at Bonnie Jean's Cocktails, a lounge in an adjacent strip center. Sparrow and his wife found Jon Murray peculiar when they came to see the car.
"His whole style was '70ish, from his acid-washed jeans to his bleached hair," Shirley Sparrow recalls.
"He looked like a barroom brawler and a heavy drinker to me. He was jittery and very arrogant," says Mark Sparrow, a former San Antonio policeman.
Despite their misgivings, the Sparrows bought the car.
Only later did they learn that their jittery Jon Murray, short and fair, did not resemble the real Jon Murray, who stood more than 6 feet tall, was dark, and spoke with a lisp.
The Sparrows believe they caught a glimpse of the real Jon Murray, and perhaps Robin as well, when they showed up to collect the Mercedes. The two were in an old pickup truck that picked up the arrogant salesman after the Mercedes was delivered.
"The one that looked like Jon Murray was driving, and the one that looked like Robin was sitting in the middle. She had to move over to let the other guy in," Sparrow says.
Since the car sale, the Sparrows have looked at numerous mug shots and photographs presented to them by reporters, but none matched.
It would be almost three years after the purchase of the car before the Sparrows saw the face of their nervous Mercedes salesman. A San Antonio Express-News reporter showed the mug shot to them last fall, and both Sparrows saw a familiar face.
"It's a very good likeness, the best yet, but I'd have to see him in person to be positive," said Mark Sparrow.
By late 1996, American Atheists officials were already weary of questions about O'Hair. Employees were discouraged from talking to the press, and President Ellen Johnson, who had replaced O'Hair as leader, ceased giving interviews.
The strategy merely fueled suspicions of a cover-up.
Late that year, the atheists inadvertently provided the first big break in the story when they filed their Form 990s, an annual disclosure required by the IRS of certain nonprofit organizations.
According to those 1995 tax statements, at least $625,000 belonging to two atheist organizations, both run by O'Hair, had disappeared at the same time as O'Hair and her two children.
"The $612,000 shown as a decrease in net assets or fund balance represents the value of the United Secularists of America's assets believed to be in the possession of Jon Murray," read the sworn 1995 tax statement.
"The whereabouts of Jon Murray and these assets have not been known since September 1995 and [are] not known to the organization at this time," read the statement.