Kyron Horman's Father Says 'Small' Chance of Wife Being Innocent

PORTLAND, Ore., July 9, 2010 — -- The father of missing Oregon second-grader Kyron Horman said there is little doubt that his estranged wife had something to do with his son's disappearance.

"I think the percentages are so small that I have no optimism in that regard, no," Kaine Horman said when asked if there was any chance his wife, Terri Horman, was innocent.

Horman, who spoke to "Good Morning America" alongside his ex-wife and Kyron's mother, Desiree Young, said Terri Horman seemed to change after the birth of their 19-month-old daughter, Kiara.

"She went through some post-partum depression after the birth and her emotional state was more erratic," Horman said.

Horman moved out of the couple's home with Kiara nearly two weeks ago after police reportedly told him they had evidence that Terri Horman had tried to hire the landscaper to kill him.

He has since filed for divorce and was granted an emergency restraining order keeping Terri Horman away from him and their daughter.

Though Kaine Horman, Desiree Young and Young's husband initially presented a united front with Terri Horman in the days after Kyron vanished last month, the family has now turned on Kryon's stepmother and is begging her to cooperate with police.

"I believe respondent is involved in the disappearance of my son Kyron who has been missing since June 4, 2010," Kaine Horman wrote in his application for the restraining order.

He added, "I also recently learned that respondent attempted to hire someone to murder me. The police have provided me with probable cause to believe the above two statements are true."

Police have not named her a suspect or person of interest in the case, but Kaine Horman and Desiree Young said she failed two polygraph tests.

Terri Horman and her attorney declined to comment on the allegations made by Kyron's parents.

Young said she didn't believe Terri Horman from the beginning when she called to tell her that Kyron went missing from his elementary school.

"There was just certain details that just didn't make any sense that gave me that sick to my stomach feeling," Young said.

At a recent press conference, she implored Terri to tell the family where he is.

"Unfortunately I am kind of at that point where I am so angry I just don't even have words," she said. "I just really want her to do the right thing ... Kyron is still out there and he needs to be home."

Kaine Horman said he feels betrayed.

"I think we all do," Young added.

Young said she would hope Terri Horman would decide to give in and start talking.

"I would like to think not, because my son is involved. But I have the feeling that she will never ever give in," she said.

" I don't think she is going to tell the truth," Kaine Horman said.

"She hasn't told the truth for seven and a half years that I have known her," Young said.