PORTLAND, Ore. (CBS/KOIN/AP) Kyron Horman's biological mother said she believes the 7-year-old's stepmother planned his disappearance just as the boy was asking to move out of the stepmother's home.
"Without a doubt, I think it was very planned," Desiree Young said in a Tuesday interview with NBC's "The Today Show."
Young reiterated on the morning show her accusation that Kyron's stepmother, Terri Horman, was involved in his June 4 disappearance, though police have not named her a suspect in the disappearance.
Before he disappeared, Kyron lived with his stepmother and his birth father in Portland. Desiree Young lives in Medford, Oregon, over 250 miles south of Portland.
"I absolutely believe that Terri Horman is responsible for Kyron's disappearance," said Tony Young, Desiree's husband and a detective with the Medford Police Department.
Terri Horman has become isolated from the family since Kyron's father, Kaine Horman, filed for divorce and requested a restraining order against her, claiming that he believes she was involved with Kyron's disappearance.
Kaine Horman also said in his request for a restraining order that investigators told him that he had been the target of a murder plot by his wife in late 2009.
According to CBS affiliate KOIN, a judge consolidated the restraining order and divorce into one case on Tuesday.
Young has said Terri Horman was supposed to drive Kyron to Eugene on the day he disappeared to turn him over to her and Tony Young to spend the weekend in Medford.
On Tuesday, Young told the morning show she had to work the day of the science fair.
"To know that I was four and a half hours away when he needed me to protect him," Desiree Young said, "the fact that I had to work that day instead of going to the science fair like I wanted to, that I feel guilty for, too."
She said Kyron was unhappy in his father and stepmother's house, and resisted being returned there.
Anyone with information on the whereabouts of Kyron Horman is asked to call the Multnomah County Sheriff's tip line at 503-261-2847.