Hawaii investigators have arrested a 66-year-old man in a Utah nursing home in connection with a five-decade old cold case murder.
DNA testing connected Gideon Castro, a US Army veteran, to the long-unsolved murder of student Dawn Momohara, 16, on March 21, 1977.
Momohara’s body was found by a teacher on the second floor of a building at McKinley High School in Honolulu, with medical examiners saying she was sexually assaulted before being strangled to death.
An orange cloth was wrapped tightly around her neck, and the murder sparked fears across the island as the girl’s killer remained at large.
Although the case went cold, DNA evidence from the crime scene including shorts and underwear worn by Momohara were preserved by law enforcement, which went under analysis in March 2019.
One year later in March 2020, forensic investigators found a partial DNA profile taken from sperm at the murder scene, leading police to the Castro family.
Gideon Castro and his brother William had initially been identified as suspects a week after the murder, and although they said they knew Momohara, neither were arrested.
Both brothers came under suspicion again in 2019 as they shared partial DNA matches. After DNA taken from William’s child ruled him out as a suspect, detectives were left to track down Gideon.
When Gideon was interviewed almost 48 years ago, he told detectives that he met Momohara at a school dance in 1976, and admitted that the two of them would speak occasionally on the phone.
This detail may have identified him as a person of interest in the case as the morning before Momohara was killed, she was known to have told her mother she got a call from an unknown person.
She told her mother that she and some friends were going to the Ala Moana Center with some friends, and as Honolulu Police Lt. Deena Thoemmes said at a press conference this week, ‘that was the last time that Dawn’s mother saw or heard from her daughter.’
After Momohara’s body was found at the school, detectives tracked down a witness who claimed that the night before the murder, he saw a man lingering in his car by the same building she was later found inside.
The car was described as a sedan likely to be a Pontiac LeMans, Buick Century or Buick Regal with louvered rear windows, a maroon bottom and white vinyl top, reports the Star Adviser.
‘The car was parked on the grass, and a male was observed walking out from the ground-floor steps,’ Thoemmes said this week. ‘The witness circled his car back around, but the male and the car had already left.’
The man was described as Asian and between 18 and 22 years old, with shoulder-length hair and around 150 pounds. Gideon Castro would have been 18 at the time of the murder.
A composition sketch was produced, but Thoemmes said that the sketch ‘failed to provide any substantial leads at the time.’
‘Despite following up on numerous leads and interviewing multiple individuals, investigators were unable to identify a suspect at that time,’ she added.
Following decades as an unsolved cold case, until the case was submitted for further DNA testing in March 2019, and the partial DNA match was found a year later.
Detectives tracked down the Castro brothers as matches to the DNA over three years later, and authorities first went to William in Chicago, Illinois in November 2023 to get a sample from him or one of his children.
When his child’s DNA ruled William out as a suspect, detectives turned to his brother Gideon, and the FBI and Homeland Security aided the investigation as they found was living in a nursing home in Utah.
After getting DNA from his son in another state using ‘covert’ methods, he was found to be a match to the sample found at Momohara’s murder crime scene, with further testing of Gideon confirming the match, Thoemmes said.
Utah cops arrested Gideon inside the nursing home and charged him with second-degree murder.
He is now awaiting extradition to Honolulu, where he will stand trial for Momohara’s murder.