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.

Nearly 50 years ago a young teacher was found stabbed to death inside a California high school on the first day of summer break. On Monday, cold case investigators identified her killer publicly for the first time.