Lyle Brent White said he was in the bathroom, heard a crash, emerged and saw his brother at the bottom of the stairs, "standing on Antonio's throat."
It was Jan. 28, 2000, the day Centennial Elementary fifth-grader Antonio Davalos disappeared. On day six of his trial on first-degree murder charges, White took the stand in his own defense.
He said he never asked Jonathan - his 28-year-old brother who has Down syndrome - what happened. Instead, White sent him to his room.
Then, after not finding Antonio's pulse, he set about trying unsuccessfully to stuff the 11-year-old's body into two household trash bags.
"'I had to protect my little brother," White said. "He means the world to me."
White, 29, said he lied repeatedly to police, a distraught Davalos family, a man he called his best friend and his and Jonathan's older brother, Roger.
Hours after he dumped Antonio's body, White feigned leaving the Davalos townhome to search for the boy.
"I really just needed to get out of there," he testified Wednesday.
Though he said he didn't know if Jonathan hurt Antonio - or would talk about whatever he'd seen - White left him behind that night. Jonathan played with Antonio's toddler sister as the family awaited word.
White said he put Antonio's body into a duffel bag that had stored his tent. He said he then brought an oblivious Jonathan to the van, drove to a bank and withdrew $16 - all the money they had. Then they ate at McDonalds, Antonio's body behind their seats.
"I don't think he remembered what happened," White said, guessing maybe the boy fell down the stairs.
During an interview in which police brought up a possible accident scenario, White is recorded as saying "Are you trying to bore me to death?" The brothers drove to Red Rocks amphitheater and cruised around Evergreen, looking for a Dumpster. They got lost in Genesee, went to Lookout Mountain and then Buffalo Bill's museum.
Back closer to the townhome, they went to return a video game to Blockbuster, White said. He said he then found a Dumpster that looked full enough to be emptied soon. Antonio was found frozen there four days later, behind a Bed, Bath & Beyond on West Bowles Avenue in Jefferson County.
White then returned to the Littleton townhouse where he and Jonathan were living with Antonio's grandmother. Antonio had stayed over the night before.
White described Antonio's head as being bent back so far it touched his back. Arapahoe County Coroner Michael Dobersen testified earlier this week that Antonio died from manual strangulation.
"So today's the day you're telling the truth? Is that what you're telling the jury?" asked deputy district attorney Eva Wilson.
White said repeatedly he wanted to protect Jonathan. He also said his relationship with Antonio was not tense, as others have testified over the past week, and that he'd never abused an ex-girlfriend's kids who on Tuesday testified that he did.
Paul Spragg, a 25-year developmental disability expert, testified about Down syndrome and the fantasy life associated with it.
"I have never seen a violent fantasy be acted out by a person with Down syndrome," Spragg said. He also said a person with Down encountering a startling incident would normally talk about it readily. The strongest indicator of whether someone with Down syndrome is violent is a previous history of violence, Spragg said. A dozen witnesses have testified that Jonathan was not violent.