Mari Bonnici's estate filed a federal civil-rights lawsuit on Sept. 8 against Sonoma County, the city of Santa Rosa and two Sheriff's Office employees, alleging that officials failed to act despite months of warnings about Deputy Jeremy Lyle before he killed Bonnici at her east Santa Rosa apartment on Aug. 10, 2025, and then died by suicide at the Sonoma County Coroner’s Office site on Chanate Road in Fountain Grove around 2 a.m. on Aug. 11. Bonnici was 38. Lyle was 44.
The lawsuit, filed in U.S. District Court, alleges local law enforcement agencies failed to intervene despite clear warning signs and calls for help, according to the Press Democrat. Bonnici worked for the Sheriff's Office as a detention specialist, while Lyle was a 10-year veteran of the department. Both killings occurred within Santa Rosa city limits, and Santa Rosa police confirmed Lyle killed Bonnici before taking his own life.
A November Incident and a Blocked Psychiatric Hold
According to the complaint, the alarm bells started ringing in November 2024, less than a year before the killing. Lyle's brother repeatedly called the Sheriff's Office asking for intervention, and the complaint alleges that on Nov. 21, 2024, Lyle struck Bonnici during an argument, bloodying her face, then locked himself inside the home with their children after pushing her out, per the lawsuit detailed by Adina Flores. The complaint alleges Lyle discussed hurting himself during that same incident and later told his brother his job was eating him alive, confessing to contemplating suicide.
The lawsuit alleges that Sheriff's Sgt. Tommy McNeil determined Lyle fit the criteria for an involuntary psychiatric hold, but that Capt. Orlando Rodriguez told McNeil not to take any action. The same account describes Rodriguez as having ordered that no hold be imposed, leaving Lyle armed and on duty.
A Later Threat, Then Continued Duty
The lawsuit further alleges that Lyle later threatened to kill a dating partner with his gun and fired it into the ground near her head, pointing the firearm at her head while making the threat. The Sheriff's Office launched an investigation after Lyle allegedly sent threatening communications to the woman's husband, a deputy — but per the lawsuit, Lyle remained on duty without restrictions despite the reported threats, retaining access to his firearms.
About a week before her death, Bonnici called Santa Rosa police to report threats and fear for her and her children's lives. The lawsuit alleges a 911 operator told Bonnici and Lyle they needed to grow up and refused to send officers. Agencies declined to comment on the pending litigation. On the evening of Aug. 10, 2025, officers located Lyle with a handgun behind his back in the bed of his personal truck during the search for him; he died by suicide before dawn after an hourslong standoff, according to the Press Democrat.
The Sheriff's Office Response
Sheriff Eddie Engram has said in public interviews that his agency would have responded had Bonnici reported domestic violence directly to the department. The Sheriff's Office has said its administrative review is complete and that it will not release the findings, citing personnel-file confidentiality protections.
The lawsuit alleged that Lyle abused the steroid trenbolone and supplied steroids to other Sheriff's Office personnel. Lyle joined the Sheriff's Office as a deputy in 2015 and became a resident deputy serving the Sonoma coast in 2019.
A Family Steps In
Bonnici and Lyle's three young children — twin daughters born in November 2023 and a son born in October 2024 — lived with legal guardians described as a paternal aunt and uncle. The couple registered as domestic partners in April 2024.
A Pattern Researchers Have Documented Nationally
A report from NorCal Public Media found 15 domestic-violence-related fatalities in Sonoma County over the preceding year, including two in the same month as that report.
Stinson's research is housed in the Henry A. Wallace Police Crime Database, which tracks 20,711 criminal arrest cases involving nonfederal sworn law-enforcement officers nationwide from 2005 through 2021 — including police officers, state troopers and deputy sheriffs.
The case echoes a more recent tragedy outside Sonoma County: a retired San Francisco police officer killed his wife and their adult daughter in their Northern California home before turning the gun on himself in Marin County, according to a report from USA Today earlier this month.
