
Just when all hope was lost, justice for a murdered high school teacher has been achieved after a shocking 47 years.
A family member of the killer finally came forward recently to confirm that a then-16-year-old confessed to the brutal 1978 stabbing at a California high school.
The admission has solved one of the state’s most perplexing cold cases, even though Peterson’s murderer will never face trial.
Diane Peterson’s life was cut short on June 16, 1978, at Branham High School in San Jose, just one day after summer break began.
The 30-year-old teacher was found with a single stab wound to the chest, killed with a knife chillingly marked “Teacher Dear.”
For nearly five decades, her murder remained unsolved despite multiple witnesses and leads.
The breakthrough came when one of the killer’s relatives finally admitted to authorities that Harry “Nicky” Nickerson had confessed to the killing minutes after it happened.
This confession confirmed what many had suspected for years: the troubled teen was responsible for the senseless murder that shocked the San Jose community.
“The relative admitted to police that Nickerson came to their home minutes after the killing and confessed to having stabbed Peterson,” officials stated.
Witnesses at the time reported hearing Peterson’s desperate cries for help.
“A student at the time heard Diane calling for help. She was saying help, help, help. That student actually saw the perpetrator flee from the scene,” explained Santa Clara County Deputy District Attorney Rob Baker.
A composite sketch based on eyewitness accounts from 1978 resembled Nickerson’s photo from the same year.
Multiple witnesses stated that Nickerson had confessed to the murder and had been seen with the knife, but initial police investigations failed to corroborate these claims.
The case took several bizarre turns over the years. In 1983, a student claimed to have witnessed the murder and identified Nickerson as the killer but later retracted their statement.
In 1984, another witness reported that Nickerson had implicated himself, suggesting the murder was related to a drug deal.
Santa Clara County District Attorney Jeff Rosen said:
“This marks the end of a terrible and tragic mystery. Ms. Peterson would have been a senior citizen today if she had not crossed paths with this violent teenager. I wish she was. I am pleased that we have solved this case, even though the murderer is not alive to face justice. I wish he was.”
Nickerson’s life after the murder followed a predictable path of crime and violence. He accumulated a criminal record that included armed robbery, assault, and kidnapping.
In 1984, he was critically injured during a drug robbery. He ultimately died by suicide in 1993, escaping justice for Peterson’s murder for 15 years.
The Santa Clara County District Attorney’s Cold Case Unit reopened the investigation multiple times, conducting extensive DNA testing between 2023 and 2024.
This persistent effort finally paid off, marking the fourth cold case solved by the DA’s Office this year and over 30 resolved since 2011.
San Jose Police Chief Paul Joseph declared:
“While the suspect will never stand trial or face the consequences for his actions, we hope this resolution brings a measure of peace to the victim’s loved ones and to a community that has carried this loss for far too long. Let this serve as a solemn reminder: no matter how much time passes, we will continue to seek the truth—because every victim matters, and every life deserves justice.”
Peterson’s family has expressed gratitude for the investigators’ persistence over 47 years.
While the resolution brings closure, it also highlights the tragic reality that they were denied the opportunity to see the killer being properly held accountable for his heinous crime.