More than four decades after a beloved California schoolteacher was found brutally stabbed to death in her home, investigators have finally unmasked her killer—closing one of the state’s most chilling cold cases. The breakthrough came after a tip from a relative revealed a long-buried family secret, ultimately leading detectives to the suspect through advanced DNA testing and genealogical tracking.
The Details About The Murder
Diane Peterson, a teacher at Branham High School in San Jose, was found dead in 1978 near her classroom with a stab wound to her chest. The school had recently for summer break, and Peterson was there to clean her classroom when she was attacked. This week, the Santa Clara County District Attorney’s Office confirmed that 16-year-old Harry Nickerson was the one who killed Peterson. Nickerson died by suicide in 1993 and had a criminal past that included armed robbery, kidnapping, and assault.
When the case was initially investigated, Nickerson was suspected but never actually convicted due to a lack of credible evidence. As time passed, multiple people came forward with statements, one person claimed Nickerson had a knife with “Teacher Dear” written on it, and another said he confessed. However, none of these claims could be fully verified.
Recent Developments In The Case
Earlier this year, the breakthrough came when one of Nickerson’s relatives told investigators that Nickerson came to their home just minutes after the murder and confessed to the killing. According to the cold case unit, this relative shared details that only someone close to the killer could have known.
Although attempts to solve the case through DNA evidence failed, this confession helped close the decades-long mystery. A family member of Diane Peterson thanked law enforcement for never giving up, saying she was a kind, loving person who is still deeply missed. This long-awaited resolution brings some measure of closure to a case that haunted the community for decades.
