Break Near in Kyron Horman Case?

The stepmother of a 7-year-old Oregon boy missing more than a month remains in seclusion while speculation grows about her possible involvement in his disappearance, reports CBS News Correspondent Ben Tracy.

There are allegations that Terri Horman tried to hire a hit man to kill Kyron Horman's father, Terri's now-estranged third husband, months before Kyron vanished.

And authorities say a break in the case may be imminent after one of the biggest probes in the state's history. Police say they've tracked nearly 3,000 leads and conducted hundreds of interviews.

"I've got to make a lot of decisions this week," says Multnoma County Sheriff Dan Staton. "It's gonna be based on ... what comes out of the investigation between now and the end of this week."

Kyron Horman's Stepmom in Murder-for-Hire Plot?
Cops: We Think Kyron's Alive
Kyron Horman's Mom to Stepmom: Come Clean
Kyron Horman's Stepmom Hires Top Lawyer
Missing Oregon Boy's Father Files for Divorce
Investigators Focus on Kyron Horman's Stepmom
Kyron Horman's Case Now Considered Criminal

Kyron's parents contend Terri Horman hasn't responded to their public pleas to fully cooperate with investigators.

Kyron's father, Kaine Horman, Kyron's mother, Desiree Young, and her husband said in an e-mail to news organizations late Monday they believe Terri still hasn't resumed speaking to law enforcement.

Kyron's parents had asked Terri to fully cooperate with investigators in a statement released Thursday.

Terri is the last known person known to have seen Kyron alive. She claims she left him at his Portland-area elementary school June 4, and she reported him missing seven hours later.

In the week that followed, investigators from 22 agencies tracked down 1,000 leads.

By week two, Terri Horman's photos were appearing on fliers, along with questions about her movements. Her truck was towed and tested for evidence, her cell phone records were examined, and she took the second of two polygraph tests.

"I think investigators know a lot more than what they're saying," observes former federal prosecutor Laurie Levenson.

In recent days, notes Tracy, more information about Terri's past has surfaced. She became a competitive body builder in 2005. In that same year, she pled guilty to a DUI charge. She married Kaine in 2007. Eight days ago, he filed for divorce and obtained a restraining order, amid the allegations that Terri tried to have him killed.

"That says to me it's likely he believed those allegations, that he wanted to distance himself from her, and that also says to me that police are now closing in on her as the most likely suspect," concludes CBS News legal analyst Lisa Bloom.

Police won't say whom they suspect or when or if they'll make an arrest, and haven't named Terri a suspect or person of interest.