On Sunday evening, a devastating murder-suicide unfolded in Sonoma County when an off-duty sheriff’s deputy fatally shot his former partner, Mari Bonnici, 38, before taking his own life during a standoff with law enforcement.

According to Santa Rosa Police, the incident occurred around 7 p.m. at an apartment complex on Quigg Drive. Jeremy Lyle, 44, an off-duty deputy and father of three, allegedly shot Bonnici while she was at home. After the attack, Lyle approached a neighbor’s door within the same complex, handed over a baby, and informed the resident that the child’s mother had been injured. The neighbor immediately called 911.

Officers arrived promptly and found Bonnici unresponsive on her living room couch. She was identified as a detention specialist with the Sonoma County Sheriff’s Office and a devoted mother of three children. The infant given to the neighbor, along with twin toddlers discovered in a back bedroom, are believed to be Bonnici and Lyle’s children. Thankfully, all three children were unharmed and are now in the care of family members.

Following the initial attack, Lyle fled the scene. Police soon found him at the Sonoma County Coroner’s Office parking lot, where he engaged in a standoff with officers. After several hours, around 2 a.m., Lyle fatally shot himself.

Authorities confirmed that Lyle and Bonnici had been in a domestic partnership but were separated at the time of the tragedy.

This heartbreaking event marks the third murder-suicide in Sonoma County in 2025 and the city’s ninth homicide, leaving the community in shock as they mourn the loss of Mari Bonnici and grapple with the ongoing effects of domestic violence.