When Katie stopped wanting to visit her dad a few years later, her parents attributed it to early adolescence, and to Katie wanting to do her own thing.
Then, one evening, Katie's mother, Janet Griffin, received an upsetting phone call from her daughter.
"I don't know why, but I just knew," Janet told CNN's "The Hunt with John Walsh."
"...And she said it was Bruce. She said, 'He's been touching me and making me touch him and I just can't go there anymore.'"
"Bruce" was Bruce Sawhill. Sawhill had been close friends with Katie's father, Ken Griffin, since high school. When Sawhill got married to his wife, Keni Jo, the new couple decided to move in a mile down the road from Ken. On occasion, Ken had allowed Bruce and Keni Jo to babysit Katie. Now, Ken raced over to his "friend's" home in a blind fury.
"I just decked him," Ken Griffin said.
How could Sawhill do the unthinkable to his good friend's daughter?
'It's always the most charming guy'
The Griffins contacted the sheriff's office and filed a report. When investigators ran a record check on Sawhill, they made a shocking discovery: Sawhill was a registered sex offender.
"It's hard to describe that kind of betrayal," Ken Griffin said.
The Griffins had always known that Sawhill had a record, but he had claimed he was busted for growing marijuana. Now they discovered that was a cover story; he had actually been convicted in St. Louis County for the sexual abuse of a 13-year-old. The official charge was sodomy.
"It's always the most charming guy," Walsh said of Sawhill, who was released on parole in 1992. "...It's always the guy that everybody loves that hides that one big dangerous, dark secret."
Sawhill was arrested again on September 25, 2001, for the abuse of Katie Griffin, and charged with two counts of sodomy in the first degree. He was released one month later on a $50,000 bond. A trial date was eventually set for October 29, 2002.
Katie overcame her fears, and decided she wanted to testify against Sawhill in court. She wanted to let everyone know what Sawhill had done to her.
"She was so worried that he may do it to another child," Janet Griffin said.
But when trial day arrived, there was no sign of Sawhill -- or his wife. They've been on the run ever since.
Numbing the pain of trauma
Katie was so distraught when Sawhill fled that her parents decided a change in scenery might help.
She agreed to go to stay with her older half-sister, Pam Hansen, who lived in Colorado. There she began seemingly adjusting to a new life, going to school and making friends right away, according to her family.
But, a year later, she was dead. Her sister found her in the basement; she had apparently suffocated while inhaling spraypaint fumes -- a cheap high known as "huffing." She was just 12 years old.
"I think [Sawhill] set into motion [the] events that led up to Katie's death. I have no doubt in my mind about that," Ken Griffin said.
"I blame Bruce for taking her innocence away, for making her grow up faster than she had to -- just not letting her be a little girl," Hansen said.
Have you seen Bruce Sawhill?
Bruce Sawhill wears a set of upper dentures. He has a distinctive loud laugh, and likes to laugh at his own jokes. He enjoys casual drinking and is known to be very sociable in bars. He has grown marijuana in the past and could be working on a marijuana farm. He's also a skilled drywall installer, plasterer and painter. It is believed he's still with Keni Jo.
If you've seen Bruce Sawhill or have any information as to his whereabouts please make the call. 1-866-THE-HUNT or go online to CNN.com/TheHunt. We'll pass your tip on to the proper authorities and if requested will not reveal your name.
See more of Sawhill's case on "The Hunt with John Walsh," at 9 p.m. ET/PT Sunday, August 23.