Charlene Jacquez, who joined the Contra Costa County Sheriff's Office two decades ago as a deputy and went on to investigate homicides and command the county's Mutual Aid Mobile Field Force, has been promoted to assistant sheriff. The office provides law enforcement services to unincorporated areas throughout the county, including communities near Walnut Creek.

Sheriff David Livingston announced the promotion on Tuesday, Aug. 18, elevating Jacquez from captain to a senior leadership post. She will oversee the Administrative Services Bureau, which covers personnel and finance, professional standards, recruiting and training for the county's largest law enforcement agency.

Livingston said he is proud of Jacquez's accomplishments and that her career-long leadership positions her well to guide the office into the future.

Jacquez succeeds Steve Simpkins, who had held the administrative services role and had been with the office since 1994. The department has not said whether Simpkins retired or was reassigned.

From dispatcher to command staff

Jacquez grew up in East Contra Costa County and started in public safety in 1999 as a 911 dispatcher and community service officer with the Galt Police Department. In 2001, she joined the Brentwood Police Department as a community service officer, a position she held for five years while attending the police academy. She graduated in 2005.

She joined the Sheriff's Office in 2006 as a deputy in the Custody Services Bureau. After transferring to field operations, she worked county patrol, the contract City of Oakley and investigations, where she handled domestic violence, sexual assault and homicide cases.

Jacquez made sergeant in 2019, serving at the Martinez Detention Facility and later in the contract City of Lafayette. She was promoted to lieutenant in 2022 and assigned as station house commander of Delta Station, then to captain in February 2025 as West County Detention Division commander overseeing the Marsh Creek Detention Facility.

Along the way, she served on the SWAT Hostage Negotiations Team and commanded the county's Mutual Aid Mobile Field Force. She is a graduate of the California POST Command College, a 14-month leadership program that requires nomination by an agency chief executive, and holds a bachelor's in criminal justice and a master's in organizational leadership.

What the role covers

The Administrative Services Bureau handles internal functions that shape the department's workforce: hiring, training, discipline and budgeting. The Sheriff's Office employs more than 1,100 sworn and professional staff serving over one million residents across 715 square miles.

"Having been born and raised in East Contra Costa County, I have a deep connection to this community and am committed to continuing to serve our residents while supporting the men and women of the Office of the Sheriff," Jacquez said in the announcement.

Residents can contact the Sheriff's Office at (925) 646-2441 or visit cocosheriff.org.