Off-duty California sheriff's deputy kills mother of his children, then himself, police say

ByCornell Barnard KGO logo
Tuesday, August 12, 2025
Sonoma Co. sheriff's deputy kills mother of his children, then himself

SANTA ROSA, Calif. -- Authorities in Northern California say an off-duty Sonoma County sheriff's deputy is dead after he fatally shot his ex-partner, who is also a sheriff's department employee, before taking his own life.

It began Sunday night in Santa Rosa, when police and SWAT negotiators were called in after neighbors called 911, reporting an incident of domestic violence.

Residents in northeast Santa Rosa say their neighborhood was in lockdown Sunday night for a manhunt.

"There were police officers coming into my cul-de-sac, there was a helicopter hovering for a few hours," said Christina Savala.

It began with a frantic 911 call from a neighbor in an apartment complex on Quigg Drive.

"We got a call from a woman in an apartment complex stating that a male partner of a neighbor had come to her apartment and dropped off an infant saying call 911 because the mother was hurt," said Santa Rosa Police Sergeant Patricia Seffens.

Police say that man was off-duty Sonoma County sheriff's deputy, 44-year-old Jeremy Lyle, a 10-year veteran of the department. He is pictured on the department's Instagram page with his K9, Rappa.

This is an undated image of Jeremy Lyle, Sonoma County Sheriff's Deputy.
This is an undated image of Jeremy Lyle, Sonoma County Sheriff's Deputy.
Sonoma County Sheriff's Department

"Officers made entry and located a deceased female victim 38-years-old and two additional young children inside the residence," Seffens said.

Police say the children were unharmed. The victim is deputy Lyle's ex-partner, Mari Bonnici. She, too, was a sheriff's department employee.

A short time later, police got notification that Lyle was parked at the Sonoma County Coroner's Office, where he refused to surrender.

"The negotiator with our negotiations team communicated on and off with Mr. Lyle until 2 a.m. Unfortunately, he took his own life with a single gunshot," said Seffens.

"It's as bad as it gets. I can't even fathom if the children saw that. I can't even imagine," said Steve Schneider, who lives in Santa Rosa.

Police are now investigating a possible motive and any history between the former couple.

"At this time, we have no reports of previous domestic violence," said Seffens.

The sheriffs department says it's mourning the loss of two beloved employees and sending condolences to their families.

If you are experiencing suicidal, substance use or other mental health crises please call or text the new three digit code at 988. You will reach a trained crisis counselor for free, 24 hours a day, seven days a week. You can also go to 988lifeline.org or dial the current toll free number 800-273-8255 [TALK].

Copyright © 2026 KGO-TV. All Rights Reserved.