‘People don’t forget;’ Utah Cold Case Coalition weights in on Hawaii cold case DNA match
Jan 22, 2025, 6:27 PM | Updated: 6:53 pm
MILLCREEK – Soon, a man living in a Utah nursing home will be sent to Hawaii where he’s facing a second degree murder charge.
66-year-old Gideon Castro is accused of killing 16-year-old Dawn Momohara nearly 50 years ago. He was arrested at a Millcreek nursing home investigators said he lives at on Tuesday morning.
Man arrested in Utah in connection with Honolulu 1977 cold case
Honolulu police said Momohara’s body was found on the second floor of a building at McKinley High School, where she was a student, on March 21, 1977.
Castro also attended the school and graduated in 1976.
Police said Momohara was strangled and sexually assaulted.
“One witness reported that on the night before Dawn died, between nine and 10 p.m., he and his girlfriend drove through McKinley High School campus and observed a car and a male near the English building,” Honolulu Police Lt. Deena Thoemmes said.
Decades-old sketches of the suspect and his vehicle didn’t bring police any answers. But new information and advanced DNA technology led police to Gideon Castro.
“There’s not enough money to do DNA testing on anywhere near all of the cold cases, but when it can be done, it’s very reliable,” said Utah Cold Case Coalition Co-founder Karra Porter.
She said results in cases like Momohara’s give families hope.
“They have mixed feelings a lot,” Porter said. “On the one hand, it brings up all of these painful memories, but on the other hand, they’re finally seeing some answers and in this case, a potential prosecution.”
She said DNA advanced technology can also deter people from committing crimes.
“I believe it leads to a deterrence in the commission of these kinds of crimes,” Porter said. “I think people now understand, ‘I can’t get away with things that I maybe thought I could get away with in the past.'”

Karra Porter, co-founder of the Utah Cold Case Coalition on Wednesday, Jan. 22, 2025. (KSL TV)
Porter said she’s studied what happens to suspects carrying secrets like an unconfessed crime, for years.
“A lot of people, this eats away at them, sometimes physically they just deteriorate,” she said.
She said some people live life as if nothing happened.
“Some people commit a heinous crime, I guess it has such an impact on them that they never commit another one, but they also don’t necessarily feel guilty about the first one,” she said. “Maybe they excuse it with, ‘I was young or I made a mistake or I was drunk or whatever.'”
Porter said some suspects don’t consider the outcome.
“What doesn’t seem to occur to them is, come forward yourself, and you have a better chance of not dying in prison,” Porter said.
She said answers in cold cases can help families rewrite their loved one’s legacy.
“It gives the family a chance to talk about what their loved one was like and have a memory of them, and let the community remember them in a positive way,” Porter said.
Castro is in Utah pending extradition. None of the law enforcement agencies involved in this case are releasing which nursing home Castro lived in.