Dad with ‘twisted plan’ fatally stabs 9-year-old son at park, California cops say
A father stabbed his 9-year-old son to death at a California park in a “twisted plan” to force police to kill him, authorities reported.
Mateusz Dzierbun, 48, of Fremont, called 911 at about 3:20 p.m. Sunday, July 13, to report a stabbing at Cataldi Park, the San Jose Police Department said in a July 14 news release.
“These officers had no idea that the frantic person on the line was in fact the suspect himself,” Police Chief Paul Joseph said at a news briefing, KTVU reported. “A deranged man who had murdered his own son.”
Officers arriving at the park found Dzierbun hunched over the child’s bleeding body with a kitchen knife in his hands, police said in the release.
He refused to drop the knife despite orders from officers, then stood, raised the knife and charged at them, police said. Officers opened fire, killing Dzierbun.
“A twisted plan to force officers to shoot him,” Joseph said at the briefing, KRON reported. ”I don’t ever remember a parent murdering a child so brutally. Suicide by cop is a cowardly act, one that draws officers into the suspect’s disturbed nightmare.”
An investigation showed the boy was Dzierbun’s son and that he had called 911 himself to report the killing, police said in the release.
“The child suffered from injuries so severe that it’s unimaginable they could have been inflicted by his own father,” Joseph said, according to KTVU.
“I cannot imagine how scared this child must have been when the person meant to be their protector became their attacker,” San José Mayor Matt Mahan said in the release. “As a parent and as a human being, there are no words to describe how horrific and heartbreaking this act of violence is.”
An investigation into the incident continues. Detectives ask anyone with information to contact them at 3638@sanjoseca.gov, 3644@sanjoseca.gov or 408-277-5283.
San Jose is about a 60-mile drive southeast from San Francisco.
This story was originally published July 15, 2025 at 9:44 AM with the headline "Dad with ‘twisted plan’ fatally stabs 9-year-old son at park, California cops say."