A teenager suspected of fatally stabbing a teacher in a California high school more than four decades ago was identified after a relative told authorities about a decades-old confession made immediately after the murder, officials said.
Harry Nickerson, who was 16 when the Santa Clara County District Attorney’s Office said he killed Diane Peterson at San Jose’s Branham High School in 1978, died by suicide in 1993.

In a news release Monday, the prosecutor’s office said an earlier witness in the case told investigators he had seen Nickerson carrying a knife with the phrase “Teacher Dear” written on it.
That account could not be corroborated, the prosecutor’s office said.
Peterson was found lying on the floor near her classroom with a single stab wound to her chest on June 16, 1978, one day after school recessed for the summer, according to the release.
Teachers were clearing their classrooms at the time.
Nickerson was treated as a suspect in the killing, according to the release. In 1983, a student’s relatives told police that the student claimed to have seen Nickerson stab Peterson, but the student denied this to authorities.

In 1984, a witness told police that Nickerson had implicated himself in the killing, according to the release.
Nickerson was later convicted of armed robbery, assault with a deadly weapon and kidnapping, and he was shot and critically injured during a drug robbery, the prosecutor’s office said.
Recent efforts to identify Peterson’s killer using DNA were unsuccessful, according to the release.
During a meeting with investigators this year, a relative of Nickerson’s told authorities that the teen had come to their home minutes after the killing and confessed.
Rob Baker, a prosecutor with the Santa Clara County District Attorney’s cold case unit, said in an email that it was unclear why the relative did not come forward sooner but the person provided a detailed statement “demonstrating unique knowledge about the crime that could have only come from someone who spoke with the killer.”
In the release, a relative of Peterson’s was quoted thanking investigators for not giving up, and saying: “Diane was a beautiful and wonderful person who is missed dearly.”