The Enemy Within III: What Drove Valessa?

Although Valessa Robinson originally took the blame for her mother's murder, it was only a matter of a few months alone in prison, away from her boyfriend Adam Davis, before she had an abrupt change of heart.

In her confession, Valessa had declared that she had stabbed her mother in her throat and then twice in the back.

Later, when asked to describe her boyfriend, Adam Davis, Valessa said, "I think he's the devil." And her story changed. Valessa claimed her boyfriend, Adam Davis, killed her mother while she was high on LSD in her bedroom.

In fact, the only thing Valessa said she's guilty of is not rescuing her mother. And for that, she had no explanation.

"I hate myself that I didn't save my mom," Valessa said. "The one chance I had to bail her out I didn't."

Everyone who knew Valessa wondered how a child so carefree and innocent could turn into an-out-of-control teen-ager.

For Michelle, her sister's troubles started at age 11, when her parents divorced. "My sister took the divorce very hard; she changed a lot when that happened," Michelle said.

After the divorce, Valessa didn't see much of her father, Chuck Robinson. He moved out of state in search of a new sales job.

Valessa was devastated about her parents' breakup and missed her father, because he was her biggest supporter.

Her mother also wasn't around much, according to Valessa's friend, Christie Collins. Vicki Robinson had a new job as a real estate broker and a busy social life.

Valessa and Michelle recalled how Valessa didn't fit in at school, how kids were mean to her.

At age 12, Valessa had been allowed to join a rock band with men in their 20s. That's when she first started experimenting with drugs, according to Valessa. In eighth grade, things only got worse. Valessa started skipping school and doing more drugs.

"Acid was the main thing that we did; we also did Ecstasy," Valessa said.

Valessa even started staying out all night.

"I don't know what Vicki could've done differently," said Vicki's new boyfriend, Jim Englert, who observed that Valessa was beyond discipline.

Then something happened during the summer after Valessa's eighth grade that Valessa's father says may have been a turning point. Vicki Robinson and Englert took a two-week family vacation to Michigan, and when Valessa refused to go, Vicki Robinson just left her young daughter behind, alone.

"I thought it was unconscionable. I thought it was nuts, said Chuck Robinson. For two whole weeks, Vicki Robinson never called to check on her daughter. Valessa was just 14.

Shortly after that vacation when Valessa started ninth grade, she met 18-year-old Adam Davis. Adam was living on the streets. His father was dead and his mother had abandoned him when he was 2. He was a high school dropout and a drug dealer.

By the time Vicki Robinson realized her daughter was out of control, Davis and Valessa had a devotion that bordered on obsession.

"Looking back, I realize that he had this overwhelming control over me," Valessa said.

Why didn't her mother try to stop the relationship? Valessa explained: "She was afraid that if she stepped in and put her foot down and said you're not seeing this guy anymore, I think she was afraid I would leave. And I probably would have."

Finally Vicki Robinson took action. Without telling Valessa, she made plans to send her daughter to a yearlong program for troubled teens called Steppin' Stone Farm.

"I had no idea," Valessa said. "She never talked to me about sending me anywhere except for my dad's."

But 10 days before Valessa was scheduled to start a program at the Steppin' Stone Farm, Vicki Robinson was murdered.

Click here to find out what the court was to consider about the fates of Adam Davis and Valessa Robinson.