Runaway Takes Off With Sex Offender

Colorado authorities are searching for a convicted sex offender and 16-year-old girl who they believe had a consensual relationship and ran away together last week.

Matthew Preston Caulk, 40, is wanted by police for not registering as a sex offender in Montana and Colorado. He was convicted in Washington state in 2002 for sexual misconduct with a child in Washington. Caulk was last seen Sept. 26 in Morrison, Colo.

Amber Westbrook, a girl with whom he had been in a relationship with for some time, according to her parents, was last seen Sept. 25 when her parents dropped her off at school in Denver.

"They have had some type of relationship," Lakewood Police Department spokesman Steve Davis told ABC News. "Whether that's an intimate one, I don't know."

Davis repeatedly stressed, however, that right now, there is "absolutely no indication of any criminal behavior," and that if Caulk were not wanted on the two warrants for not registering as a sex offender, they would not by law be able to detain him.

"We don't have a crime here," Davis said.

He acknowledged that some people have had a difficult time understanding that, and that it probably does little to satisfy the girl's parents, "but there's no law, so far, that's been broken."

That will change, Davis added, if investigators determine that Caulk and Westbrook engaged in sexual activity.

Kimberley Maloney, Amber Westbrook's mother, told ABC News' Denver affiliate KMGH that she and her husband had warned their daughter about spending time with Caulk.

"She told me she was capable of making her own decisions and was basically saying she was making wise decisions," Maloney said. "And we got into an argument and she left."

Roger Westbrook, the girl's father, told KMGH he'd actually confronted Caulk, telling him that he should start hanging around with people his own age. It was the elder Westbrook who contacted police when he discovered online that Caulk was a registered sex offender in Washington state.

Monday, a convicted sex offender with a violent history ran away with a 15-year-old girl in Florida. William Joe Mitchell had met the girl on the social networking Web site MySpace and developed an online relationship with her. The girl sneaked out of her family's house in the middle of the night.

In that case, an Amber Alert was issued and the local sheriff's office implored the public to help find the pair. The girl was dropped off at a Wal-Mart location 400 miles from her home. While she is safe, authorities continue to hunt for Mitchell.

Matthew Caulk is described as a 5-foot-7-inch white male, weighing 140 pounds, with a shaved head and multiple tattoos. Amber Westbrook is also 5 feet, 7 inches, with blond hair and blue eyes.

The pair could be travelling in a green Volkswagen Golf or a Mercury Cougar with Nebraska plates.