MEDFORD, Ore. -- In an exclusive interview on NBC's Today Show, Kyron Horman's mother said she thinks the missing 7-year old's step-mom could have hurt her son 'in the worst way.'

Desiree Young appeared on Today Monday morning. She talked about explosive emails that police showed her just last Friday. The emails were sent to friends by Terri Moulton Horman, Kyron's step-mother, according to Young.

'I now believe without a shadow of a doubt that not only is she (Terri) capable of hurting Kyron, but that it's clear she could have hurt him in the worst possible way, ' said Young, as she struggled to talk through the tears.

But what were in those emails?

Young said she couldn't go into specifics because of the ongoing investigation. But she didn't hold back about the ugly picture she said the emails painted.

'It's very clear from Terri's horrible words that she had a severe hatred for Kyron and that she blamed a lot of the marital problems on Kyron,' said Young.

Kyron Horman went missing from Skyline Elementary School on June 4th. While Terri Horman has not been named as a suspect, she has clearly remained the focus of the investigation.

Desiree Young and Kyron's father Kaine Horman have long provided a united front in the search for their son.

But on Monday, Desiree indicated she was seriously disappointed with Kaine for failing to share with her information of Terri's alleged issues with alcohol.

'I just can't stand by and support the choices that he's making. He had several opportunities to let Tony (Desiree's husband) and I know what was going on and he did not, ' she said.

Young also said that she tried to get custody of her son a year before Kyron disappeared, but Kaine would not allow it. Young said Terri even called her on the phone to urge her to take over custody of Kyron because he was so upset.

'He (Kyron) was exhibiting some problems in school, expressing a lot of sadness, and upset at the situation. Kyron on many occasions said he wanted to live with me, ' she recalled.

NBC's Merideth Vierra ended the interview by asking Desiree if she still has hope that Kyron is still alive.

'I will until the day I die, ' said Young.

Kaine has scheduled a press conference for 10:30 Monday, from the Wall of Hope created as a show of support from the community for Kyron and his family. KGWwill cover that event.