OAKLAND — A former Martinez resident who died by suicide last year in Oregon was the person who raped and killed a 32-year-old woman while she was jogging in Tilden Regional Park in November 1990, authorities announced Wednesday.
Jon Lipari was named as the killer as a result of modern DNA technology and law enforcement team work involving East Bay Regional Park District police, the FBI, the Contra Costa County District Attorney’s Office and the Contra Costa County Crime Lab, and the Curry County Sheriff’s Office in Oregon, authorities said.
He was 70 when he fatally shot himself in November, 2024, in Gold Beach, Ore., where he was living. Authorities said he was not aware at the time of his death he had become the prime suspect in the case.
East Bay Regional Park District Police said Lipari is the person who killed Maria Jane Weidhofer, who was described at the time by those who knew her as a gentle, soft-spoken woman. She was raped and strangled with a rope on Nov. 15, 1990, along the Nimitz Trail in Tilden Park about a mile north of the Inspiration Point lookout. Investigators said they have not found any links between Lipari and Weidhofer prior to the deadly encounter. Nor have they determined a motive.
Investigators on Wednesday said pictures of a suspect generated in 2017 by specialized DNA phenotyping, the process of predicting physical appearance and ancestry from unidentified DNA evidence, were similar in appearance to Lipari.
The break in the case was announced at a press conference Wednesday morning that included representatives from the four agencies at the park district’s Richard C. Trudeau Conference Center on Skyline Boulevard.
EBRPD police, the lead agency in the investigation, had worked diligently on the slaying for decades without identifying a suspect and provided details Wednesday about what led them to Lipari.
EBRPD police Detective Christopher Rudy said Wednesday that in 1997 biological evidence found on Weidhofer from the suspect was sent to the crime lab and was later submitted to a national database, but there were no matches at the time.
In 2020, EBRPD police began working with the FBI and the collaboration included the use of advanced DNA techniques that determined Lipari to be a potential suspect. He became the primary suspect in 2024, authorities said.
The investigation determined he was living in Gold Beach, Ore. and in early November 2024 he was found deceased in his home by local law enforcement. DNA from the scene was collected by the Curry County Sheriff’s Office, a direct comparison was done by the Contra Costa County Crime Lab and “it was a match,” Rudy said.
According to earlier media accounts, Weidhofer was a gentle, soft-spoken woman known as a free spirit.
She had moved from Southern California to Oakland two years earlier to pursue her art. She worked at a natural foods business in Oakland and painted, sketched and had hoped to follow in her painter father’s footsteps as an artist. She had won departmental honors when she graduated from U.C. Davis with a bachelor’s degree in art.
She had jogged almost daily for 10 years and often ran alone in Tilden Park.
In a 2005 Oakland Tribune story about the killing, which investigators had deemed a “cold case,” her mother, Jane Weidhofer, said the family did not consider her death a “cold case because we have had to live with the loss of a daughter and a sister every day of our lives.”
At Wednesday’s press conference, both EBRPD General Manger Sabrina Landreth and Police Chief Roberto Filice praised investigators for “never giving up” on solving the case and that the entire district was always with her family.
“I hope this brings a little bit of solace and closure” to her family, Landreth said. Added Filice, “every victim deserves justice and we work for that. Justice has been served.”
Rudy read a statement on behalf of the family from Weidhofer’s brother, Hans Weidhofer.
“Thirty-five years ago our family was irreparably harmed by the loss of Maria,” her brother wrote. “In the ensuing years our parents, Jane and Karl, struggled mightily with psychological repercussions including the frustration of knowing the perpetrator was likely still free. Maria, the family, and the world had been carelessly cheated and deprived of her future.
“On behalf of our immediate and extended family, we would like to express our gratitude to law enforcement for their unceasing efforts in finally bringing some measure of closure to this tragedy.
“We shall remember Maria as a gentle soul pursuing her dreams as an artist and baker in the Bay Area community she loved. Our wish is that she will be remembered for the person she was, and not for what happened to her.”