A Sonoma County deputy fatally shot his ex-partner, also a sheriff’s department employee, before taking his own life during a standoff with police on August 11, 2025.

The incident began when a neighbor called 911 after Deputy Jeremy Lyle, 44, appeared at her door holding an infant, saying the child’s mother was hurt. Officers found his ex-partner, 38-year-old detention specialist Mari Bonnici, dead inside the Santa Rosa apartment. Their three children—twin toddlers and an infant—were unharmed.

Police later located Lyle outside the county coroner’s office. After hours of negotiations, he died by suicide around 2 a.m. Authorities called it a domestic violence-related murder-suicide. Bonnici had recently filed to end their domestic partnership and had custody of the children.

“This incident brings profound shock and concern to our community,” said Sgt. Juan Valencia. Residents described the lockdown as “intense,” with helicopters and armed officers searching the area.

Loved ones remembered Bonnici as “a devoted mother” who “adored her three kids.” A GoFundMe has raised nearly $24,000 to support them. Her sister, Amie Porter, said, “They were her entire world.”