The 1978 cold case murder of California high school teacher Diane Peterson, who was stabbed to death, has been solved this year, officials confirmed.

Investigators have solved the cold case murder of a San Jose teacher stabbed to death at Branham High School nearly 50 years ago, naming a teenager who was originally suspected in the crime as the killer.

A then-16-year-old student, who is now dead, is officially named as the killer of Diane Peterson near her Branham High School classroom nearly five decades ago.