16-year-old found dead inside high school in 1977, Hawaii police say. Now arrest made
A grim discovery was made at a Hawaii high school in 1977, one that would pose a mystery for decades.
Student Dawn Momohara, 16, was found dead inside McKinley High School on Monday, March 21, 1977, according to the Honolulu Police Department.
“A teacher had found her and it was early in the morning, second floor of the English building,” Susie Chun Oakland, a former student, told KHON in 2019.
For days, the school was abuzz about her death, she told the outlet.
“I think all of us (were) really shocked,” Oakland said.
Now, nearly five decades after her death, an arrest has been made, Lt. Deena Thoemmes of the Honolulu Police Department said in a Jan 21. news conference.
Through DNA testing, Gideon Castro, 66, was identified as a suspect in Momohara’s death, Thoemmes said.
Last seen alive
The day before she was found dead, Momohara told her mother she was going to the Ala Moana Center with some friends, Thoemmes said.
“That was the last time that Dawn’s mother saw or heard from her daughter,” Thoemmes said.
When she never returned home that Sunday, her mother reported her missing at about midnight, the Honolulu Star-Bulletin reported in 1977.
Body found
The next day, police responded to a possible homicide at McKinley High School just after 7:30 a.m., Thoemmes said.
Momohara was found dead, “lying on her back, partially clothed,” Thoemmes said.
“An orange cloth was tightly wrapped around her neck,” Thoemmes said.
Some of Momohara belongings were found “at the scene, including her purse, slipper, shorts and other evidence,” according to Thoemmes.
Through an autopsy, the medical examiner determined her cause of death was asphyxia due to strangulation, Thoemmes said, adding that her death was ruled a homicide.
The medical examiner also found injuries that suggested Momohara had been sexually assaulted, according to Thoemmes.
Investigation
At the time, police were trying to determine if Momohara, who was described as “very quiet and shy,” ever made it to the shopping center, the Honolulu Star-Advertiser reported in 1977.
“As part of this investigation, detectives interviewed numerous friends, family and acquaintances of Dawn,” Thoemmes said.
Among those interviewed were Castro and his brother, according to Thoemmes.
Castro told police he met Momohara at a school dance in 1976 and that he graduated later that year, Thoemmes said.
Castro said he and his brother were friends with Momohara, Thoemmes said.
He told police he last saw her at a school carnival in February 1977, “where they talked for about 15 minutes,” Thoemmes said.
“He said that he told her that he was in the Army Reserve and had returned to Honolulu earlier that year,” Thoemmes said.
Detectives also interviewed his brother, who said he met Momohara at a school dance in 1976 and that they occasionally spoke over the phone, Thoemmes said.
He told detectives the last time he saw Momohara was three days before her death when he offered a ride to school but she declined, Thoemmes said.
A witness
A witness told police the night before Momohara’s death, he was driving through the McKinley High School campus when he saw a man near the English building, Thoemmes said.
The witness said he saw a car parked on the grass, and a man “walking out from the ground floor steps,” Thoemmes said.
By the time he circled back around, the man had already left in his car, Thoemmes said.
The witness provided a description of the man, which was later used to create a composite sketch that was released to the public, Thoemmes said.
However, the sketch “failed to provide any substantial leads at the time,” according to Thoemmes.
“Despite following up on numerous leads and interviewing multiple individuals, investigators were unable to identify a suspect at that time,” Thoemmes said.
‘Fast forward 42 years’
After decades of stagnation, the case finally had a break.
“Let’s fast forward 42 years to March 20, 2019,” Thoemmes said.
Cold case detectives submitted evidence, including Momohara’s shorts and underwear, for DNA testing, Thoemmes said.
Through testing the shorts, criminalists got a partial DNA profile for an unidentified man in May 2020, Thoemmes said.
More than three years later, information led detectives to believe Castro or his brother were potential suspects, according to Thoemmes.
Detectives first went to Chicago, Illinois, in November 2023 to try to get a DNA sample from the brother or one of his children, Thoemmes said.
They were able to get a sample from one of his children, which through testing ruled out Castro’s brother as a suspect, according to Thoemmes.
Detectives turned their sights to Castro, who lived in Utah and had a son in another state, Thoemmes said.
After getting a DNA sample from the son, testing found that he was the biological child of the unknown man from Momohara’s case, Thoemmes said.
Detectives then got a DNA sample from Castro and testing confirmed he was a suspect in Momohara’s killing, according to Thoemmes.
A warrant for Castro’s arrest was issued, and Utah police arrested him inside a nursing home on a second-degree murder charge, Thoemmes said.
Castro is now awaiting extradition to Honolulu, where he will stand trial in Momohara’s death, according to Thoemmes.
This story was originally published January 22, 2025 at 1:38 PM with the headline "16-year-old found dead inside high school in 1977, Hawaii police say. Now arrest made."
