For nearly half a century, the murder of 16-year-old Dawn Momohara haunted the close-knit community of Honolulu. Found partially clothed and strangled with an orange cloth in her high school in March 1977, the case remained unsolved—until now. Thanks to modern DNA technology, police have arrested a former classmate in connection with her death.

On Tuesday, Gideon Castro, 66, was taken into custody at a Utah nursing home. Authorities say advanced DNA testing linked him to the crime, a breakthrough that wasn’t possible back in the ‘70s. Castro, who attended the same high school as Dawn, had previously told investigators he knew the victim but denied involvement in her death.

The tragic discovery of Dawn’s body sent shockwaves through McKinley High School and the city of Honolulu. Classmates and teachers remember the quiet, shy teen who never returned home after telling her mother she was headed to a shopping center with friends. Her body was found the next morning outside a classroom, plunging the community into fear and grief.

For decades, the case went cold despite exhaustive efforts by detectives. Witnesses recalled seeing a man and a car near the school the night of the murder, but no suspect was identified—until now. In 2019, investigators revisited the case, using cutting-edge DNA analysis on evidence from Dawn’s clothing. They eventually traced the genetic profile to Castro through samples taken from his son.

Susie Chun Oakland, a former classmate, expressed relief at the arrest. “I’m happy for her family that this case was resolved,” she said. “It’s sad there are so many other cases that are not. But I’m glad we have people and professionals, as well as the community, who have not given up.”

Dawn’s mother, who last heard from her daughter the day before her death, now has a chance for closure, even if it’s decades later. The arrest serves as a reminder of how far forensic science has come—and how persistence can bring justice, even after nearly 50 years.

“It’s just caring for one another,” Chun Oakland said, reflecting on the tragedy. “That should guide us in our life and how we live it.”