A former San Francisco Police Department deputy chief and her 24-year-old daughter were found dead alongside her retired police officer husband in a California home Sunday evening in what authorities are investigating as a suspected murder-suicide.

Ann Mannix, 65, who once served as deputy chief of the San Francisco Police Department, was killed alongside her 24-year-old daughter, Katie. Ann’s husband, Kevin Mannix, 68, a former police sergeant, was also found dead at the property. Authorities are investigating the case as a suspected murder-suicide.

Her career also saw her rise to leadership positions overseeing two major areas of the department’s operations.

Investigation underway

The three victims were discovered at a residence in Marin County, across the bay from San Francisco, after deputies responded to a report of gunfire Sunday evening.

Ann’s achievements within the San Francisco Police Department spanned several decades.

Department records show that she was appointed deputy chief of the Field Operations Bureau in 2018. She moved into a leadership role with the Special Operations Bureau in 2019.

Police Chief Derrick Lew shared the news with department employees, describing the agency as receiving it “with heavy hearts.”

He also reminded staff that support was available to those struggling with the news.

“Please keep their family in your prayers. BSU is available to all members who may need it during this difficult time.”

Had a long career in law enforcement

Kevin retired from the San Francisco Police Department in June 2018 after spending 27 years on the force.

In a farewell letter published by Taraval Station the following month, he reflected on the friendships he had made during his service and his plans to devote more time to his personal life.

“I leave the SFPD, but I am taking your friendships with me forever,” he wrote.

The deaths of Kevin, Ann, and their daughter have prompted an emotional response from the San Francisco Police Officers Association, which said the tragedy had affected both serving officers and retirees.

In its statement, the organization wrote: “It is with profound sadness, shock, and heavy hearts that we address the devastating news that emerged out of Marin County on Sunday evening.

“The tragic loss of retired Deputy Chief Ann Mannix, her daughter Katie, and retired Sergeant Kevin Mannix in a suspected murder-suicide has left our entire SFPD family reeling. “There are no words that can fully capture the depth of this tragedy, nor are there simple answers to the painful questions we are all asking.

“Ann Mannix was a trailblazer in our department—becoming the first woman to join and lead the SWAT team, and rising to lead both the Field Operations and Special Operations Bureaus.

“Many worked alongside Kevin during his 27 years of dedicated service at Taraval Station and beyond. To see their lives, and the life of their 24-year-old daughter Katie, end in such a horrific and senseless manner is a burden that weighs heavily on every officer, active and retired.”

Her best friend’s heartbreaking goodbye

One of the most personal tributes came from a woman who told The Post that she had been Ann’s best friend for 60 years.

Her message reflected the shock and heartbreak surrounding the former deputy chief’s death.

“This is so sad for me. She was my best friend of 60 years. Love her, she didn’t deserve this.”

San Francisco Mayor Daniel Lurie also shared his condolences, recognizing Ann’s long service to the city and the significance of her achievements in law enforcement.

“I am deeply saddened by the tragic deaths of retired SFPD Deputy Chief Ann Mannix and her daughter, Katie.

“Deputy Chief Mannix dedicated decades of her life to serving San Francisco. She was a trailblazer in the police department, becoming the first woman to join and lead the SWAT team and rising to lead both the Field Operations and Special Operations Bureaus.”

Where to get help

On the topic of mental health, don’t be afraid to ask for help. If you, or someone you know, is struggling, you can call or text 988 or chat at 988lifeline.org. You can also reach the Crisis Text LineMHA to 741741, or contact the SAMHSA Disaster Distress Helpline at 1-800-985-5990.

If your distress feels unbearable, or if you have suicidal thoughts or plans, contact a psychiatric emergency unit immediately or call 911.

For more information about available resources, visit Mental Health Americaat mhanational.org.