Kyron Horman's Dad Bluntly Tells Court He Suspects Step-Mom in Boy's Disappearance

Search for Missing Boy Kyron Horman Now a Criminal InvestigationCourtesy: Multnomah County Sheriffs Office
Pictured is Kyron Horman. Police leading the search for a 7-year-old Oregon boy who disappeared from his school 10 days ago announced today that their effort is now focused on a criminal investigation.

The father of Kyron Horman stated in a court document that he believes his wife, who is Kyron's step-mother, was involved in the disappearance of the 7-year-old boy who vanished more than a month ago, and that police have given him information to bolster that suspicion.

Kaine Horman and his ex-wife Desiree Young have pleaded with Terri Horman to cooperate with the investigation into what happened to their son, suggesting they suspect the step-mother was involved in his disappearance.

But the husband bluntly states in a request for a restraining order that he blames his current wife for whatever happened to Kyron.

VIDEO: Why Terri Horman Called 911Play
Botched Sting Operation Complicates Search for Kyron Horman

"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 to the court.

He adds, "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."

The restraining order was unsealed by the circuit court in Multnomah County, Ore., today after the county's Major Crimes Team told the court they no longer believed that releasing the information "would undermine their investigation into the disappearance of Kyron Horman."

The release of the restraining order came as it was revealed that a potential opportunity to arrest Terri Horman was thwarted by an ill-executed sting operation at the family's home last month.

VIDEO: Could Kyron Still Be Alive?Play
Could Kyron Horman Still Be Alive?

ABC's Portland affiliate KATU is reporting that the landscaper police say Terri Horman allegedly contacted to kill Kaine Horman was in on the sting, but then raised the woman's suspicions enough that she called 911.

The landscaper showed up at Horman's door June 26 wearing a hidden microphone to demand hush money. Undercover agents were nearby. But the plan backfired when Horman called police to report an emergency, according to KATU, telling the dispatcher a man at her door wanted $10,000.

VIDEO: Allegations suggest that Horman tried to hire a landscaper to kill her husband. Play
Stepmother Terri Horman Accused of Hiring Landscaper to Kill Husband Caine

KATU cited sources as saying that was the second call of the day. The first came minutes earlier to report that someone in a truck was threatening her.

Responding officers found themselves face to face with the undercover agents and Horman was not taken into custody.

Kyron Horman's Step-Mom Has "Anti-Freeze in Her Veins"

Police have been circling Horman in the disappearance of 7-year-old Kyron, who vanished from his elementary school science fair more than a month ago. But she has not been named a suspect or a person of interest.

"This gal seems to have anti-freeze in her veins. I mean she's under a lot of pressure," retired Portland police captain C.W. Jensen told ABC News. "I mean the investigation, the family turning against her, the community turning against her, a divorce a separation from her child -- all these that's a lot of pressure but it seems that she has the hubris so far to push herself through."

VIDEO: After a month with no trace of Kyron, the family still hopes for his safe return.Play
The Search Continues for Missing Kyron Horman

Kaine Horman moved out of the house, taking the couple's toddler daughter with him, apparently after learning of his wife's murder-for-hire plot. It was then that a third call was placed from the Horman home that day, listed only as a custody issue. Kaine Horman filed for divorce and was granted a restraining order two days later.

"Hopefully I think the goal was to get her to talk about the case," former FBI special agent Brad Garrett told "Good Morning America." "Arrest her and that additional pressure would get her to talk."

Terri Horman has since hired a prominent defense attorney. She denied the allegation when confronted by detectives, The Oregonian reported, and she has not been charged, though the investigation is proceeding, the sources told the newspaper.

Garrett said the attempted police sting leads him to believe police think she has either direct or indirect knowledge of where Kyron is.

But, he noted, there is the chance that she's been telling the truth -- that she has no idea where her stepson may be.

"That's entirely posible," he said. "We've never heard anything from an evidence stand point that Terri knows where Kyron is."

But the second-grader's family appears to think otherwise.

Kyron's biological mother recently pleaded with Terri Horman to start talking and help the family find their little boy.

"To Terri, you need to do what is right," Desiree Young said. "Please cooperate with investigators and the attorneys to help bring Kyron home."

Kryon's Family Clings to Hope That Little Boy Will Come Home

Even as the family struggles with Kyron's disappearance and allegations against Terri Horman, experts say unwavering hope that he'll be found alive is a powerful motivator.

Ernie Allen, president of the Center for Missing & Exploited Children, said statistics show most missing children are eventually found.

"We know from the Justice Department data, even in the most serious cases most of the children come home," he said. "You always look at those closest to the child. You rule things out. You rule suspects out."

Kryon's family said they are clinging to hope that he will come home to the room that has remained untouched since June 4.

In a statement this week, the family said they haven't even made Kyron's bed so that it looks like he slept there the night before.

"We remain hopeful because we haven't been given any information by law enforcement to indicate he isn't still alive," the statement read, "and therefore we will always expect that he will come home to us."

Allen said that's exactly the right attitude to have. He pointed out that even children missing for months or years come home, citing the Elizabeth Smart and Jaycee Dugard cases. And, he noted, both of those cases were broken by "average citizens" who reported seeing something out of the ordinary.

He urged anyone near the Portland area to stay vigilant and do the same for Kyron.

"We hope that people out there will think what they have seen, what they know… might be a key break to bring Kyron home," he said.

Terri Horman said she last saw him walking to his classroom after the two of them had attended a pre-school science fair together.

The school said he never made it to class, but he was not reported missing until the end of the day, when he did not get off the school bus that was supposed to bring him home.

Kyron's disappearance has triggered the biggest search in Oregon history.