Alleged kidnapper indicted: Grand jury files 10 charges against Duncan Mahi

Duncan Mahi appears in Kona District Court Wednesday for a preliminary hearing. (Laura Ruminski/West Hawaii Today)

A Big Island grand jury on Wednesday indicted the 52-year-old Hilo man accused of kidnapping and sexually assaulting a 15-year-old girl this weekend just hours after a preliminary hearing in the case was continued.

Duncan Kealoha Mahi’s preliminary hearing got underway as scheduled Wednesday morning in Kona District Court. However, after just three witnesses took the stand, prosecutors moved to continue the hearing until Thursday because two witnesses were unavailable.


Mahi was charged Monday afternoon with two counts each of kidnapping, first-degree terroristic threatening and first-degree robbery, and one count each of methamphetamine trafficking and first-degree sex assault in connection with alleged crimes that began around 1:30 p.m. Friday at Anaehoomalu Bay in South Kohala.

According to police and the victim’s mother, the victim was with her boyfriend, also age 15, at Anaehoomalu Bay when a “local” man in his 40s to 60s approached the young couple, forced the girl to tie up her boyfriend and then took her at knifepoint.

The abduction triggered Hawaii Island’s first-ever Maile (AMBER) Alert as county, state, federal and private assets searched for the teen. The victim was able to escape her captor around 11:30 a.m. Saturday in Hilo with the assistance of Good Samaritans.

Police later informed the public they were looking for Mahi in connection with the kidnapping. Within 90 minutes of putting out an emergency alert asking for help tracking down the man, Mahi was in police custody.

Though the victim’s name was widely disseminated via the AMBER Alert and continues to be reported in the media, West Hawaii Today is not including her name in stories to protect the victim’s identity because she is a minor and a victim of sexual assault.

At the preliminary hearing Wednesday, a Hawaii Police Department Sgt. Bradden Kimura testified that police first learned of the alleged abduction when the 15-year-old boy was able to borrow a beachgoers phone to call 911. The officer said dispatchers said the juvenile was hysterical when he called, stating he had been robbed at knifepoint and his girlfriend had been taken.

When officers arrived at Anaehoomalu Bay, the boy still had blue painter tape stuck in his hair, with remnants still on his wrist and ankles. Kimura said the area where the two youths were at the time of the abduction was approximately 1/4 mile south of Lava Lava Beach Club where he observed discarded zip ties, towels and a beach umbrella.

Hawaii Police Department Evidence Specialist Mary Midkiff testified she recovered four beach towels, an umbrella, one backpack, a bag, drink bottles and a bag of chips from the area of the alleged abduction. Approximately 300 feet south of the area, she recovered a gray T-shirt with one of the sleeves torn off laying over a log and a gray spaghetti strap dress.

Midkiff said the day camp site was in a private spot in the shade amongst keawe brush. She also stated fingerprint and DNA testing has yet to be completed on the evidence recovered.

A third officer, Brandon Mansur, added that detectives were also able to get surveillance video from the King’s Shops and Queens MarketPlace after the suspect had been arrested that showed Mahi’s vehicle in the area around the time of the abduction.

Following the testimony of the three police department members, the case was continued to Thursday. However, around 1:45 p.m. the grand jury indictment was handed down charging Mahi making Thursday’s continuation moot.

Mahi was indicted on two counts kidnapping, first-degree terroristic threatening, and third-degree sexual assault and one count each first-degree robbery, meth trafficking-distribution to a minor, first-degree sexual assault of a minor, and first-degree sexual assault.

Mahi is also subject to extended terms of imprisonment due to his previous felony convictions for first-degree terroristic threatening. If convicted, the indictment states, Mahi may be sentenced to a mandatory minimum period of imprisonment without the possibility of parole as a repeat offender.

As of press time Wednesday, a time and date for Mahi’s arraignment and plea in Circuit Court had yet to be set.

Mahi remains in custody at Hawaii Community Correctional Center in lieu of $2 million bail.

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