Alderden said sheriff's deputies searched the Heenes' home three times, but never looked in the rafters above the garage because they did not think the area was accessible to a small child. He said the boy climbed on top of a box to get to the attic.
Alderden added that officials believed it was possible that the aircraft was capable of carrying the boy, answering some critics who claim the flight was a hoax because the device could not conceivably carry that weighty a payload.
Police released a 911 tape of Falcon's parents frantically calling 911 to report that their son was stowed away in the floating balloon.
It was Falcon's mom, Mayumi, who called 911, but she was so distraught, the dispatcher could barely understand what she was saying through her tears about her son floating away in a "flying saucer."
"Does he know how to operate the flying saucer?" the dispatcher asked. "No," the boy's mother wails.
Falcon's father Richard then got on the phone, but he was so distracted that he kept leaving the dispatcher saying, "Hello? Hello?"
When asked if he was certain Falcon was in the aircraft, the father responded: "Yeah, we looked everywhere. And then [another] son just said ... yeah, he verified it ... He said, 'yeah, he went inside just before it went off.'... We had it tethered; it wasn't supposed to take off."
Richard Heene warned the dispatcher that the balloon was headed for a nearby airport.
Toward the end of the call, the 911 dispatcher was left repeating, "Helloooo. Sir? Hellooo?" She then said to a colleague, "My caller is completely gone."
Richard Heene spent Friday on the defensive, saying Falcon was found safely hiding in the rafters of his family's garage and insisting that the balloon's takeoff was an accident and not a publicity stunt.
"To have people say that, I think, is extremely pathetic," Richard Heene told "Good Morning America" Friday, his arm wrapped around son Falcon. "We were holding on to every second, every second, just hoping he might come out OK."
Making the rounds on the morning news programs, Richard Heene explained what he believed Falcon meant when he said, "We did this for a show." The dad told NBC's "Today" that Falcon had showed journalists his hiding place in the garage rafters.
"Somebody had asked [Falcon] if he would show them how he got in the attic, so he was obliging them, and one of the guys told him it was for some TV show. So, that's what he was referring to. That's what he was referring to when he made that statement," Heene said.
Heene and law enforcement officials told reporters Thursday that Falcon had retreated to his hiding space after his father scolded him for fiddling with the experimental aircraft tethered in the family yard.
"I was in the attic, and he scared me because he yelled at me," Falcon told reporters. "That's why I went in the attic."
"Falcon is a great kid, very adventurous, and has no fear factor," neighbor Tina Sanchez said. "For him to climb into this balloon would not be out of character."
Richard Heene, responding to the recent criticism, said, "I'm not selling anything. This is what we do all the time," he said. "I don't have a can of beans I'm trying to promote. This is just another day in the life of what we do."
ABC News' Michael James and Clayton Sandell contributed to this report.