“The caller was hysterical, stating the assailant was still on scene and gave a description of the suspect that officers later discovered exactly described the caller himself,” Joseph said.
When officers arrived, they saw Mateusz Dzierbun, 48, of Fremont, hunched over a bloody child on the ground, armed with a large knife, Joseph said.

Joseph said officers “pleaded with the suspect to drop the knife,” but Dzierbun didn’t cooperate “and instead made several statements indicating he intended to be shot by the police.”
Dzierbun then stood up with the knife raised and charged at officers, who fired on him. Joseph said a sergeant with 19 years of experience and an officer with about four and a half years both fired their weapons.
Other officers were present with “less lethal” weapons, but Joseph said, “They weren’t able to try those options before [Dzierbun] forced the issue.” Officers arrived at the park around 3:31 p.m., and the shooting occurred about three minutes later, he said.
When officers reached the child, Joseph said the boy was already “clearly deceased,” and “suffered from injuries so severe that it’s unimaginable they could have been inflicted by his own father.”
Both officers are crisis intervention-trained and were wearing body cameras.
“The officers who responded that afternoon were running toward what they believed was a child desperately in need of help. They came intending to save a life, not to take one,” Joseph said.
“They had no way of knowing that this horrific and unfathomable act of violence had already led to the loss of an innocent child’s life before they even arrived. Now these officers have to carry a weight that was never theirs to bear, but one that was placed squarely on their shoulders by a man whose final act was as selfish as it was senseless,” he added.