(CNN) -- Three days after the world watched a giant balloon fly through the air and a tearful family express fears that their 6-year-old boy could be inside, authorities announced what millions already suspected: The whole thing was staged.
It was carried out by a couple who met "in acting school in Hollywood" and "put on a very good show for us," Sheriff Jim Alderden of Larimer County said Sunday. Authorities know there was "a conspiracy" between Richard and Mayumi Heene, he said.
"It has been determined that this is a hoax," the sheriff said, adding police "believe we have evidence at this point that it was a publicity stunt" by the family in hopes of "better marketing themselves for a reality show at some point in the future."
The dramatic announcement included an admission by Alderden that authorities misled the media on Friday when they said they still believed it was not a hoax.
In fact, after a comment on CNN Thursday night by Falcon, the 6-year-old boy, "it became very clear to us at that point that they were lying," Alderden said. But in order to get to the truth, "it was very important that they maintain their trust with us." So investigators misled the media while they carried out their "game plan" of gathering the truth. VideoWatch Alderden tell how police recognized "hoax" »
The words that triggered concern: "You guys said we did this for the show." That's what Falcon told his parents when they asked him, on live television, why he had not come out from hiding when they were calling for him.
The "nonverbal responses" from the children at that moment made it clear, Alderden said. The children looked at their parents at that moment, seeming unsure how to react. VideoWatch body language expert analyze Heene interview »
The Heenes denied any hoax Friday during an interview with CNN and said Falcon's remark was a reference to the media that had assembled in front of the family's home.
The Heenes had no immediate response to Sunday's announcement.
Charges have not been filed, but authorities expect to recommend felony charges including conspiracy, contributing to the delinquency of a minor, and attempting to influence a public servant, Alderden said. They also plan to recommend a charge of filing a false police report, which is a misdemeanor.
He also said it is "unlikely" that someone convicted of these charges would face jail time. "We have to allocate our space to" those who commit more serious crimes or have a record of felonies, he said.
One key question remains unanswered, Alderden said: Where was Falcon as police searched for him? On Friday, Alderden said it had been determined that the boy was hiding in an attic in the garage and had fallen asleep. Now, authorities are unsure. Alderden said the boy may not even have been in the home. Explainer: How 'balloon boy' drama began »
"The biggest error we made is when we searched the house, very clearly we didn't search the house as thoroughly as we should," he said. Authorities had assumed a 6-year-old boy could not have reached that attic, he said, so they were willing to believe the story the Heenes told the next day.
The Heenes have previously appeared on the ABC program "Wife Swap." Richard Heene chases storms and brings the family along.
After the Hollywood gossip Web site TMZ.com reported that the Heenes had been "pitching a reality show about the wacky family," one of the networks mentioned -- TLC, which produces the show "Jon and Kate plus 8" -- told CNN that "they approached us months ago, and we passed."
He has been described as a meteorologist, but his education ended at the high school level, Alderden said.
Alderden also said authorities are concerned about the safety of the three children, ages 6, 8 and 10. In fact, authorities spoke with Mayumi Heene "at length about domestic violence" and the children's safety, Alderden said. "But we didn't have enough that would allow us or Child Protection Services to physically take the kids from that environment."
There was a 911 call from the home earlier this year that led authorities to a "suspicious circumstance" that Alderden said may have involved "domestic violence, perhaps against the wife."
In an interview Friday with CNN's "American Morning," the Heene parents -- looking exhausted -- expressed relief that their son was alive. "I'm feeling very, very grateful that Falcon is among us," Richard Heene said.
Mayumi Heene said that the family was sitting in their living room, distraught and terrified for missing Falcon, when he walked into the room.
"[It] felt like from nowhere. When I first saw him, I couldn't even believe it. I couldn't comprehend right away," she said, adding that the next moment she was "just jumping, calling his name." She began to "scream and cry, and I just enjoyed that moment."
But I didn't see the one with this couple on it. That show seems to attract a lot of nutbars!
The other family they swapped with were a couple freaks too.
That's just so wrong.