Nearly 50 years ago Dawn Momohara was found strangled to death on the second floor of the McKinley High School English building in Honolulu, Hawaii. Now investigators believe they have found the culprit in a Utah nursing home.

Momohara was a 16-year-old sophomore when investigators say her classmate, Gideon Castro, sexually assaulted and strangled to death using a scarf on March 21, 1977.  

Police at the time interviewed both Gideon and his brother William but both denied allegations. An eyewitness report placed someone with a similar look and driving a similar car as Castro at the school on the night of the murder. There was not enough evidence at the time, however, to continue prosecution.

Thanks to advances in DNA evidence, however, the cold case was given new life.

Honolulu Police in conjunction with the Greater Salt Lake City Unified Police Department’s Millcreek Investigations Unit were able to narrow a DNA match to a partial major DNA profile before matching to Gideon Castro.

The effort to close the case began in 2019 and used the resources of both police departments.

“Sheriff Rivera’s highest priority is public safety, the Salt Lake County Sheriff’s Office is always willing to help other police agencies in holding those who commit violent crimes accountable,” said the Salt Lake County Sheriff’s Office in a statement. “Honolulu PD should be commended for solving this cold case and finding justice for the victim and her family.”

Castro is currently held awaiting extradition to Utah.

A variety of new technologies have made it easier for police to investigate and solve cold cases including more than 600 cases solved using Investigative Genetic Genealogy. The Department of Justice has established a special program at the Bureau of Justice Assistance to aid state and local authorities in forensic analysis to solve cold cases.