Police arrived within minutes to the home and reached out to the person who made the initial call. That person had left the home, according to the sheriff's office.

The perimeter around the residence was secured for further investigation. Detectives with the sheriff's office investigations unit were still at the scene Sunday night.

9 The couple's three children Katie, Lauren and Kevin are pictured. Facebook/@katie.mannix.5

9 Kevin Mannix is understood to have murdered his wife and daughter at a home in Marin County on Sunday night. abc7

 There is no known threat to the community,  they said, according to the San Francisco Chronicle.

Ann climbed the ranks of the San Francisco Police Department, becoming deputy chief of the Field Operations Bureau in 2018 before taking charge of the Special Operations Bureau in 2019, according to department records.

She also made history as the first woman to serve on the department's SWAT team and eventually lead the unit.

9 The family are seen in an undated photo posted on social media. Facebook/@

Her husband Kevin retired from the SFPD in June 2018 after serving 27 years on the force.

In a farewell letter published by Taraval Station the following month, he looked back on the friendships he had built throughout his career and expressed his desire to spend more time with loved ones.

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

After the shooting Sunday night, San Francisco's Police Officer's Association said in a statement:  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. 

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