Hilo man accused of abducting teen in 2022 pleads no contest to kidnapping, sex assault charges

A man accused of abducting a teenager in September 2022 has pleaded no contest to charges of kidnapping and sexual assault.

Duncan Mahi, 54, of Hilo, entered his plea Tuesday in Kona Circuit Court. He remains in custody, is being held without bail and is ordered to appear for sentencing on March 14, 2025.

“Our Office values victim input and the importance of victim well-being,” said Prosecuting Attorney Kelden Waltjen. “Sexual assault cases, especially those involving minors, are some of the most traumatic types of criminal victimization. The victims and their families were consulted and very involved throughout the plea negotiations in this case. They confirmed their support of this agreement and resolution of the case.”

Charges stem from an incident on Sept. 16, 2022, where Mahi reportedly robbed two teenagers at knifepoint at Anaehoʻomalu Bay in West Hawaiʻi. According to court documents, Mahi forced the girl to tie up her teen boyfriend before he took her to his East Hawaiʻi home.

A MAILE AMBER Alert was issued for the girl. She escaped from Mahi nearly 24 hours later after convincing him to take her to get food at Café Pesto in Hilo.

Mahi was indicted by a Hilo grand jury on Sept. 21, 2022, for the charges.

Initially charged with 11 offenses, Mahi pleaded no contest to the following:

Count 1: Kidnapping, a class A felony, carries a mandatory minimum of 13 years and 4 months.

Count 2: Kidnapping, a class B felony, carries a mandatory sentence of a minimum of 6 years and 8 months.

Count 8: First-degree sexual assault, a class A felony, carries a mandatory minimum of 13 years and 4 months.

Counts 1 and 8 will be served concurrently to each other and consecutive to Count 2 for a combined total of 30 years and have a 20-year mandatory minimum total.