Modern DNA testing leads to arrest in 1977 killing of Honolulu teen Dawn Momohara

CNN

26-01-2025

Susie Chun Oakland was a sophomore when she arrived at McKinley High School in Honolulu – a crime scene – that Monday morning nearly a half century ago.
One of her teachers had just found the body of another student on the second floor of the English building, Chun Oakland said. Dawn Momohara, 16, was partially clothed, with an orange cloth tightly wrapped around her neck, police said. She appeared to have been sexually assaulted and strangled.
In a close-knit community in Hawaii's capital and most populous city, nerves were frayed long after the discovery of Dawn's body on March 21, 1977.
'It was our first experience with a crime like that. It was very sad that someone actually died that way,' said Chun Oakland, program coordinator for an Oahu senior center that offers services to kupuna, the Hawaiian term for elders. 'People were afraid. In our state, we take care of each other, you know. We grow up looking out for one another.'
Still, it would be decades before authorities would name a suspect in the teen's killing.
On Tuesday, Gideon Castro, 66, a McKinley High School graduate who previously told police he knew the victim, was arrested at the Utah nursing home where he lived, Honolulu Police Department Lt. Deena Thoemmes told reporters.
Castro was charged with second-degree murder after DNA testing not available in the 1970s helped identify him nearly 50 years later, Thoemmes said. It's not clear if he has an attorney.
'I'm happy for her family that this case was resolved,' Chun Oakland, a former state legislator, said of Dawn. 'I'm sad there are so many other cases that are not. It's a mix of emotions. But I'm glad we have people and professionals, as well as community, that have not given up.'
Dawn's mother last heard from her daughter the day before she was found dead. The teen had received a call from an unknown male that Sunday morning, and later told her mother she was going to a shopping center with friends, according to Thoemmes.
When Dawn did not return home that night, friends and family drove around the school campus looking for her, the Honolulu Star-Bulletin reported at the time. It was not clear whether the teen – described by classmates as quiet and shy – made it to the shopping center. Dawn was reported missing hours before her body was found outside a classroom.
In the days after Dawn was killed, Thoemmes said, detectives interviewed her friends, family and acquaintances. Police released sketches of a man and a car that two witnesses described seeing near the school's English building the night before she was found dead.
Castro and his brother were among the schoolmates detectives interviewed during the initial stages of the investigation, Thoemmes said.
Castro at the time told police he had met Dawn at a school dance in 1976, the year he graduated. He said he last saw her at a carnival the following year, when they talked for about 15 minutes and he told her he was in the US Army Reserve, according to Thoemmes.
'Despite following up on numerous leads and interviewing multiple individuals, investigators were unable to identify a suspect at that time,' she said.
It wasn't until 42 years later, in 2019, that cold case detectives – aided by modern DNA testing – began making headway in the investigation following analysis of evidence from Dawn's shorts and underwear, Thoemmes said.
Investigators in 2020 were able to get the partial major DNA profile of an unidentified male from the sample obtained from the shorts, according to the lieutenant.
In 2023, investigators received information that Castro or his brother could be 'potential suspects' in the case, said Thoemmes, without elaborating. Detectives learned where the brothers were living and traveled to the mainland US to surreptitiously obtain DNA samples from children of the Castros.
A DNA profile obtained from one of the brother's children cleared him, Thoemmes said, and attention turned to Gideon Castro.
The sample taken from the son of Gideon Castro showed that his father was a match for the DNA found on Dawn's shorts, according to the lieutenant.
Earlier this month, detectives went to Utah and surreptitiously obtained a DNA sample from Gideon Castro – which tests showed matched the DNA profile taken from the shorts, Thoemmes said. He was arrested at 7:40 a.m. Tuesday at a Utah nursing home.
Chun Oakland, who was a sophomore at McKinley High School when Dawn was killed, said she learned of Castro's arrest from staff and members of the senior center where she works. She lamented that Dawn was denied a chance to be a wise and nurturing kupuna to younger generations.
'It's just caring for one another. That should guide us in our life and how we live it,' Chun Oakland said as she helped a senior prepare for an appointment. 'I don't know (Dawn's) family but I hope for her relatives at least there's closure.'