Overview

• The incident unfolded around 3:23 p.m. Sunday near Cataldi Park in the Berryessa neighborhood when 48-year-old Mateusz Dzierbun allegedly stabbed his 9-year-old son to death.
• Investigators say Dzierbun placed a 911 call falsely reporting an unknown assailant was attacking his son to lure officers into the park.
• Arriving officers encountered Dzierbun armed with a knife and shot him dead after he charged at them, with no officers injured.
• Police Chief Paul Joseph confirmed Dzierbun had no prior criminal record, mental health history, or documented domestic violence.
• The shooting marks the department’s second fatal use of force in one week and has prompted an active investigation into both the homicide and law enforcement response.