The brutal murder of a 16-year-old Hawaii student has been solved after nearly 50 years thanks to modern DNA testing, CNN reports.

Susie Chun Oakland was a sophomore when she arrived at McKinley High School in Honolulu, Hawaii, USA—a crime scene—that Monday morning nearly a half century ago.

One of her teachers had just found the body of another student on the second floor of the English building, Chun Oakland said.

Dawn Momohara, 16, was partially clothed, with an orange cloth tightly wrapped around her neck, police said. She appeared to have been sexually assaulted and strangled.

In a close-knit community in Hawaii’s capital and most populous city, nerves were frayed long after the discovery of Dawn’s body on March 21, 1977.

But it would be decades before authorities would name a suspect in the teen’s killing.

Gideon Castro, 66, a McKinley High School graduate who previously told police he knew the victim, was arrested at the Utah nursing home where he lived, Honolulu Police Department Lt. Deena Thoemmes told reporters.

Castro was charged with second-degree murder after DNA testing not available in the 1970s helped identify him nearly 50 years later, Thoemmes said.