Suspect in 1978 Teacher's Fatal Stabbing in California Identified as Teenager
A Decade Old Murder Case at Last Solved
A student suspected of stabbing a teacher in a California high school more than four decades ago has been identified, thanks to a relative coming forward with a long-hidden confession. The suspected student, Harry Nickerson, was only 16 at the time he is believed to have killed Diane Peterson at San Jose’s Branham High School in 1978.
The Santa Clara County District Attorney's Office disclosed the information, stating that Nickerson ended his life by suicide in 1993. In a news release on Monday, the prosecutor's office mentioned an earlier witness in the case who claimed to have seen Nickerson carrying a knife with the words "Teacher Dear" etched on it. However, this account could not be corroborated.
Peterson was discovered lying on the floor near her classroom with a single stab wound to her chest on June 16, 1978. It was the day after the school year had ended, leaving teachers present to clear their rooms.
Nickerson was initially treated as a suspect. Few years later, a student's family informed police that the student had claimed to have witnessed Nickerson stabbing Peterson. Yet, the student denied this to authorities. Furthermore, in 1984, a witness revealed Nickerson had admitted to the crime, but this, too, remained unsubstantiated.
Recent attempts to identify Peterson's murderer using DNA were unsuccessful. However, this year, a relative of Nickerson shared that Nickerson had confessed the crime shortly after it occurred.
Rob Baker, a prosecutor with the Santa Clara County District Attorney's cold case unit, communicated through email that the reason the relative did not come forward earlier is unknown, but their detailed statement provided unique knowledge about the crime that could only have come from someone who spoke with the killer.
A relative of Peterson's expressed gratitude to the investigators for not giving up. They expressed, "Diane was a beautiful and wonderful person who is greatly missed."
Insights: The case of Diane Peterson's murder went unsolved for nearly five decades. In 2025, a significant revelation was made that finally identified the suspect. The suspect, Harry Nickerson, took his own life in 1993, preventing him from being brought to trial.
[1] Santa Clara County District Attorney's Office[2] San Jose Mercury News[3] NBC Bay Area[4] The New York Times
[1] The striking revelation of Harry Nickerson's confession for the murder of Diane Peterson, a decade old unsolved case, was disclosed by the Santa Clara County District Attorney's Office, shedding light on the facts that were buried for nearly five decades.
[2] Amid general news and politics, the crime-and-justice section of newspapers, such as the San Jose Mercury News, reported on the discussed murder case, while platforms like NBC Bay Area and The New York Times also shared updates on related investigations and court proceedings throughout the years.
