The stunt two weeks in the planning was a marketing ploy by Richard and Mayumi Heene, who met in acting school in Hollywood and have appeared on the ABC reality show "Wife Swap," Larimer County Sheriff Jim Alderden said. The Heenes have reportedly been working on a reality TV deal in Los Angeles.
Investigators are examining the possibility of other conspirators, "including the possibility that even some of the media outlets may have had some knowledge about this," Alderden said.
Documents show that a media outlet has agreed to pay money to the Heenes with regards to the balloon incident, Alderden said. He didn't name the media outlet, but said it was a show that blurs "the line between entertainment and news." It wasn't clear whether the deal was signed before or after the alleged hoax, or whether that media outlet was a possible conspirator.
Alderden did not name an outlet or provide any details. "Let's call it (my statement) short of speculation that a media outlet was in on the hoax, but let's not discount the possibility," he said.
Six-year-old Falcon Heene may not have even been hiding in the rafters of the family's garage during the intense five-hour search for him Thursday, Alderden said.
"For all we know he may have been two blocks down the road playing on the swing in the city park," the sheriff said.
The stunt temporarily shut down Denver International Airport and caused the National Guard to scramble two helicopters in an attempt to rescue the boy, who was believed to be inside the flying-saucer shaped homemade balloon that hurtled more than 50 miles across two counties.
The drama played out on live television to millions of viewers worldwide. When the balloon landed without the boy in it, officials thought he had fallen out and began grim search for his body.
In fact, the balloon - which was held together with duct tape - would not have been able to launch with the 37-pound-boy inside, Colorado State University physics professor Brian Jones has determined.
The parents weren't under arrest, the sheriff said. He said he expected to recommend charges of conspiracy, contributing to the delinquency of a minor, making a false report to authorities and attempting to influence a public servant. Federal charges were also possible.
The most serious charges are felonies and carry a maximum sentence of six years in prison and a $500,000 fine. Alderden said they would be seeking restitution for the costs, though he didn't have an estimate.
The cost for just the two military helicopters was about $14,500.
Richard and Mayumi Heene were shopping for snacks at Wal-Mart with their three sons as Alderden told reporters that the whole thing was a hoax.
Richard Heene told The Associated Press he was "seeking counsel."
"This thing has become so convoluted," Heene said as tears welled in his eyes. He said his wife was holding together better than he was.
The couple's attorney, David Lane, issued a statement later Sunday saying the Heenes were willing to voluntarily turn themselves in to face charges. Lane said he advised the family against making public statements.
The sheriff said all three of the Heenes' sons knew of the hoax, but likely won't face charges because of their ages. The oldest son is 10. One of the boys told investigators he saw his brother get in the balloon's box before it launched.
Heene, 48, a storm chaser and inventor, has described himself as an amateur scientist, but Alderden said Heene has only a high school education.
"He may be nutty, but he's not a professor," Alderden said.
Alderden said that during the drama, the family's actions led them to believe the story was genuine. But during an interview on CNN Thursday night, Alderden said investigators had an "aha" moment when Falcon turned to his dad and said what sounded like "you had said we did this for a show" when asked why he didn't come out of his hiding place.
On Friday, Falcon got sick during two separate TV interviews when asked again why he hid.
Alderden said they didn't question the family Friday because they wanted to keep the family's cooperation by maintaining the appearance that they believed their story. Richard Heene was asked to stop by the sheriff's office under the pretext that he needed to pick up his balloon, and was questioned once he got there.
With Heene gone, other investigators went to the house. Alderden said they were looking for computers, e-mails, phone records and financial records.
Records show that police have responded to the house at least twice in the past year, including a possible domestic violence incident in February. No charges were filed.
Alderden said officials tried Saturday to persuade Mayumi Heene, 45, to go to a safe house, but she declined.
"We talked to her at length about domestic violence, about her safety, about her children's safety," the sheriff said. "We have a concern, but we didn't have enough that would allow us or child protective services to physically take the kids from that environment."
Alderden said the children were still with the parents Sunday morning, and child protective services had been contacted to investigate the children's well-being.
"Clearly, from all indications, Mr. Heene has somewhat of a temper," Alderden said.
As to the hoax that could end up with one or both in prison: "It certainly got big and whether anybody realized it that it would get the type of international media attention, I suspect this is probably beyond what they thought," Alderden said.
Associated Press writers Catherine Tsai and P. Solomon Banda in Denver, and AP contributor Breck Larson in Fort Collins provided material for this report.