Troubled teens in National Guard camp face toughest challenge yet

This is the fourth in a series of reports on the Youth Challenge Academy program and the cadets trying to turn their lives around. CBS News will follow their progress, giving frequent updates through December. The first segment: National Guard program puts dropouts on a new track ; second: From high school dropouts to cadets; and third: Tears and hugs for once-troubled teens at National Guard camp

After weeks of rigorous training, a group of cadets -- attending an academy near Los Angeles -- made their first visit home.

When 17-year-old Crista Hopkins arrived at Sunburst Youth Challenge Academy in July she was a year behind in school and looking to learn from the mistakes she made back home.

"I was really disobedient," said Hopkins. "I'd always talk back to my teachers and also my dad. I just wanted a life changing experience and I thought I could get that from here."

In the past four months she's overcome plenty of mental and physical challenges - but today could be the start of the most challenging one yet.

"Dismissed!" announced a Sergeant.

With that announcement, Hopkins and the rest of the cadets would get their first three-day home pass. For many of them, home is the place where their lives went wrong. For Hopkins, it's the place where she learned words can be used to say something painful.

"Words hurt more than anything, especially when it's by someone you love," Hopkins had told us when we first met her.

She was asked who that "someone" was.

"My dad, cause when I was messing up during school and all that, he would say 'you're going to end up like your mom did' and that really affected me a lot, because my mom, like, messed up really badly."

With tears in her eyes Hopkins added: "I don't want to end up like my mom."

She hasn't seen her mother since 2007. Chris Grimmett, who is not her biological father, adopted her when no one else would.

"I could have been homeless or dead but he decided to take me in," said Hopkins.

With Grimmet sitting by her side, Hopkins told us she appreciated him.

"I'm glad she appreciates me," Grimmet said. "I wanted that for a long time and there for a while I thought for sure we would end up being enemies."

"Not really having my mother around," responded Tucker.

The second Sunday of July, 'Intake Day' at Sunburst, was the last time he saw his mother. He was obviously disappointed when she didn't show up on 'Family Day.'

"I really love her to death," said Tucker. "I hope for the best wherever she's at. To be honest, I wanted her to be here."

She's been in and out of his life since he was three. So his grandmother, Lynette Richardson, has had to step in.

"I can't really put a reason on why she leaves, cause she's not an addict or anything like that, she just goes," said Richardson. "And I always tell her when she comes back, don't leave, stick it out."

Tucker was asked if having his grandmother was enough.

"She's more than enough," he responded. "That's the best thing in my life, is her, cause I wouldn't be anything without her."

On Monday it was back to the base.

"Welcome home!" belted Sergeant Timothy Edwards as he greeted returning cadets. But not everyone would return.

Cadet Vanessa Mejia, a member of Sgt. Edwards' platoon, was a no show. Her refusal to return prompted Edwards to call her.

"Explain to me what is going on cause we've worked too hard, we've come too far for us to allow you to give up this easy," said Sgt. Edwards on the phone.

He called her back twice, pleading with her to finish.

"She says it's family problems," Sgt. Edwards said as he hung up the phone. "And she'll regret it, come tomorrow, if we don't get her back in here today."

Despite Sgt. Edwards' strong pleas, and even a visit to her house that night, Cadet Mejia did not return to Sunburst. So far, eight teenagers have dropped out since they began in July. 208 remain.