Three people were found dead inside a home on Strawberry Circle in Strawberry on Sunday, Oct. 11, in what investigators believe was a double murder-suicide.

The Marin County Sheriff's Office said preliminary findings indicate a suspected double murder-suicide involving three people. Investigators identified the suspected shooter as male but did not publicly name him.

The sheriff's office said dispatchers received a 911 call at 5:03 p.m. reporting shots fired inside the residence. Strawberry is an unincorporated community near Mill Valley.

Deputies responded and contacted the caller, who had safely escaped the home. After securing the area, deputies entered the residence and found three people dead. Authorities said there was no ongoing threat to the community.

The sheriff's office identified the deceased as retired San Francisco Police Department (SFPD) Deputy Chief Ann Elizabeth Corriea Mannix, 65; retired SFPD Sgt. Kevin M. Mannix, 68; and their daughter, Katherine Elizabeth Mannix, 24.

The San Francisco Chronicle, citing sources familiar with the investigation, reported that Kevin Mannix shot and killed his estranged wife and daughter before taking his own life. The sheriff's office has not publicly confirmed that account.

Ann Mannix served 27 years with the SFPD before retiring as deputy chief in 2021. She was the first woman to join and later lead the department's SWAT team, according to the San Francisco Police Officers Association. The SFPD promoted her to deputy chief of the Field Operations Bureau in 2018Kevin Mannix retired from the SFPD in June 2018 after 27 years of service.

SFPD Chief Derrick Lew notified department personnel of the deaths Sunday night, writing in a department-wide message that the agency shared the news "with heavy hearts," according to the Chronicle.

In a statement Monday, the San Francisco Police Officers Association expressed grief over the deaths and recognized Ann Mannix's groundbreaking career. The association also encouraged officers and their families to use available mental health support services.

Detectives and the Marin County Coroner's Office had completed processing the scene by the time of the sheriff's Oct. 12 press release. Autopsies were scheduled for Tuesday, Oct. 13.

The investigation remains in its early stages. The sheriff's office said additional information would be released as it becomes available.

If you or someone you know is affected by domestic violence, call the National Domestic Violence Hotline at 800-799-7233 or visit thehotline.org.

If you are having suicidal thoughts, call or text 988 to reach the 988 Suicide & Crisis Lifeline.