A man accused of luring a teenage girl into a charity's delivery van in 2004, injecting her with crystal meth and sexually assaulting her was sentenced yesterday to 20 years in prison.

Anton Myklebust II pleaded guilty on Nov. 29, 2006, to kidnapping, giving crystal meth to a minor, credit-card theft and second-degree robbery in the Oct. 2, 2004, incident. But he insisted he did not rape the 17-year-old girl and that the sex was consensual.

Under the plea agreement, prosecutors dropped sexual assault charges but Myklebust is required to register as a sex offender.

"This was a horrific case, one of the most heinous cases I have ever seen in 19 years of prosecuting sex assaults," deputy prosecutor Thalia Murphy said.

Myklebust was a driver for Big Brothers Big Sisters of Honolulu when he lured the girl into the van by asking her for directions to School Street. He held her captive for eight hours.

The girl was "disarmed by the fact that it was a Big Brothers donation truck," Murphy said. "She thought it was safe."

Myklebust recently filed a motion to withdraw his guilty plea because of the sex offender registry requirement, but the motion was denied yesterday by Circuit Judge Karl Sakamoto.

Sakamoto set a minimum prison term of six years and eight months before Myklebust can be considered for parole.