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Kyron Horman's Stepmom in Affair, Kidnap Try?

The father of missing Oregon seven-year-old Kyron Horman has filed court papers containing new accusations against Kyron's stepmother -- the last person known to have seen him alive before he vanished early last month after attending a science fair at his Portland-area school.

Kaine Horman charges that Terri Horman began a sexual relationship with a childhood friend of his during the investigation of Kyron's disappearance, and attempted to kidnap their 20-month-old daughter, Kiara, reports "Early Show" national correspondent Hattie Kauffman.

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"Even if authorities suspect but can't prove Terri Horman was involved in Kyron's disappearance," points out retired Multnomah County Sheriff's Office Capt. Bruce McCain, "the next-best-thing is to arrest and charge her with a separate, ujrelated crime."

The latest complaint dates back to June 26, three weeks after Kyron vanished.

That day, Kaine left his home when investigators informed him that Terri had allegedly tried to hire a landscaper to kill him.

Two days later, Kaine asserts, as he was about to file a restraining order, Terri tried to kidnap Kiara.

Then, Kaine claims, on June 30, Terri began an intimate relationship with Michael Cook and shared sealed legal information on the Kyron probe with Cook.

Last Thursday, Kaine and Kyron's mother, Desiree Young, went public with their suspicion that Terri was involved in Kyron's disappearance, and revealed Terri had failed two polygraph tests.

Police haven't officially named Terri a suspect or person of interest.

Says McCain, "They need evidence. … Police may have enough probable cause to arrest Terri Horman, but the endgame here is not arresting her; that simply begins the prosecution."

Terri has agreed to vacate the home she and Kaine shared - the one he moved out of when get filed for divorce and got the restraining order, Kauffman says.

What impact could the new developments have on the investigation? "Early Show" co-anchor Harry Smith asked Criminal profiler Pat Brown:

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