A 66-year-old US Army reservist was arrested in a nursing home in Utah for the murder and sexual abuse of his classmate in a Hawaii high school 48 years ago.

Nearly five decades after the murder of Dawn Momohara, then 16, police investigators were able to solve the cold case using new forensics technology centering on DNA.

Like all Momohara’s classmate in the sophomore class at McKinley High School in Honolulu, Gideon and William Castro were questioned by the police following the March 21, 1977 slaying.

Despite police questioning, investigators found nothing that would have incriminate either of the Castro brothers to the murder.

After 48 years, DNA technology pointed to Gideon as Momohara’s lone attacker.

Now a senior citizen, Gideon was arrested in a nursing home in Utah where he is a resident. He faces a second degree murder charge that is penalized in Hawaii with a maximum sentence of life imprisonment.

Dawn was found dead at the second floor of a building at McKinley High School. Investigators said the victim was partially clothed but had an orange cloth tied around her neck.

Autopsy report revealed that Momohara had been strangled to death. Evidence of sexual assault were also indicated.

DNA sample was lifted from the victim’s clothing but since identification using DNA have not yet full progressed then, no suspect could be linked to the murder.

It was in 2020 that a cold case detective took the DNA evidence for forensic examination that would then utilize new laboratory technology.

Around September 2023, the Castro brothers have been identified as possible source of the DNA sample. Both were then interviewed and denied any link to the gruesome crime.

Lt. Deena Thoemmes of the Honolulu Police Department went to Chicago to secretly obtain a DNA sample from one of William Castro’s children and used it to compare with the crime scene find.

This excluded William as the killer , leaving his brother Gideon the lone suspect.

Thoemmes said Castro will be extradited to Honolulu to face charges.