Board of Directors
LUCKY CHESTNUT
Lucky was hired by the Office of the Sheriff in 2004 and is currently a Sergeant. He has held positions in every detention facility, patrol, the contract city of Orinda, Investigations, and the Sheriff’s SWAT team. He was elected to the DSA’s Board of Directors in 2009, became Vice President in 2015, and President in 2024. Since 2009, he has participated in several contract negotiations, assisted in bringing the Probation Department into the DSA, handled numerous grievances and proudly represented our members.
ANTHONY ROSSI
Anthony was hired by the Office of the Sheriff in 2006 and is currently a Sergeant, assigned to the contract city of Orinda. He is longtime member of the Sheriff’s SWAT team and has held assignments as a narcotics investigator in the Special Investigations Unit, the J-Team, patrol and detention. Anthony was elected to the DSA’s Board of Directors in 2018 and became Vice President in 2024.
ERINN RILEY
Erinn was hired by the Officer of the Sheriff in 1997 as a Dispatcher and his currently a Dispatch Supervisor in the Communications Center. She has held positions as the Training Supervisor, Training Instructor the Sheriff SWAT team as a Tactical Dispatcher and the Peer Support Team. In 2006 Erinn was elected to the DSA’s Board of Directors and the Secretary position. Erinn serves as the Director-at-Large for the DSA for the Police Officers Research Association of California (PORAC) and is the Secretary for the Bay Area Chapter of PORAC. Prior to joining the Office of the Sheriff, Erinn was a dispatcher for the City of Davis Police Department.
TOM MAGUIRE
Tom was hired by the Office of the Sheriff in 2020 and has worked at all three detention facilities and is currently assigned to the Sheriff’s Recruiting Unit and instructs at the Sheriff Law Enforcement Training Center. Tom was elected to the DSA’s Board of Directors in 2022 and became the Treasurer in 2024. Prior to joining the Office of the Sheriff, Tom completed a full career with the California Highway Patrol where also served on their association’s Board of Directors. Deputy Maguire is also a United States Navy veteran
CRISTINA HERNANDEZ
Cristina Hernandez was hired with the Probation Department in 2002 as a Deputy Probation Officer. She started in Juvenile Probation in General Supervision Unit working cases in Bay Point, Pittsburg, Antioch, and Concord. She worked in the Sex Offender Unit for two and half years in both Central and East County. She is currently assigned to General Adult Supervision working cases in Walnut Creek, Danville, San Ramon, Blackhawk. She has been a Director on the DSA Board since February of 2018 after the retirement of the prior director. She was voted back on the Board in 2023. She has been part of the Negotiations Team in the last two negotiations with the County.
CODY CASTELLUCCIO
Cody was hired by the Office of the Sheriff in 2015 and is currently assigned to the Recruiting Unit. He has worked assignments in both detention and patrol, including a Resident Deputy at Delta Station. Cody is a member of the Sheriff’s SWAT team and is was elected to the DSA’s Board of Directors in 2023. Prior to joining the Office of the Sheriff, Cody served in the United States Army.
COLIN BALKE
Colin was hired by the Office of the Sheriff in 2007 and is currently a Sergeant assigned to the Transportation Unit. He has held various assignments in Court Security, Detention, Patrol, and Investigations. Colin was elected to the DSA Board of Directors in 2023.
SHAWNA PLILER-Director Shawna was hired by the Office of the Sheriff in 2001 and is currently a Sergeant. She has held positions in detention, patrol, investigations, coroner’s division, and the Office of Emergency Services. She was also a peer support coordinator and is still an academy instructor. She was elected to the DSA Board in 2024.
DON RYAN
Ryan was hired by the Office of the Sheriff in 2006 and is currently the Patrol Administration Sergeant, assigned to the Field Training Program. He has held positions in every detention facility, Patrol station, and the Sheriff & #39's SWAT team. He was elected to the DSA’s Board of Directors in 2020. DANNY STARK-Director Danny was hired by Contra Costa County Probation in 2012 as a Juvenile Institution Officer. He works at both Orin Allen Youth Rehabilitation Facility and Juvenile Hall as a JIO. He was promoted to an Institutional Supervisor in 2021 at the Orin Allen Youth Rehabilitation Facility, after its closure in 2022 he was transferred back to Juvenile Hall to supervise the Secure Track youth of the Briones Youth Academy. This unit houses all serious offenders of Contra Costa County as well as all the youth who returned after the closure of the Division of Juvenile Justice. Danny was elected to the DSA’s Board of Directors one 2022.
DANNY STARK
JAMIE ENEA
Jaime was hired by the Office of the Sheriff in 2013 as a Dispatcher. She is a Communications Training Officer, participated in the Dispatch Recruiting Program, and is a US Air Force veteran. Jaime was elected to the DSA’s Board of Directors in 2023.
JEFF RODIER
Jeff joined the Office of the Sheriff in 2004 and is currently assigned to the Investigation Division, supervising the Violence Suppression Unit. He was elected to his second term on the DSA’s Board of Directors in January, 2024. He is a veteran of the US Air Force.
PATRICK MAZERSKI
Patrick joined the Office of the Sheriff in 2011 and is currently assigned to the Investigation Division’s Special Victims Unit, where he leads the High Tech Crimes Unit. He has previously worked held Detention, Classifications, Patrol, Discovery Bay Resident Deputy, and is a senior member of the Sheriff’s SWAT team. He was elected to his second term on the DSA’s Board of Directors in January 2024.
ROBERT JIMENEZ
Robert Jimenez was hired by the Office of the Sheriff in 1999 and is currently a Lieutenant. He held positions in every detention facility, patrol, the contract city of Oakley, Investigations (detective and detective sergeant), and the Mutual Aid Mobile Field Force (MAMFF) team. Robert joined the DSA's Board of Directors in 2023 to represent our management members.
SHAWNA SOMMERS
Brian Fitzgerald
Brian joined the Office of the Sheriff in 2006 and is currently the Sergeant supervising the Marine Patrol/Air Operations Unit. He has held assignments in
Detention, Classifications, Patrol, the J-Team, and Investigations. He is a senior team-leader on the Sheriff’s SWAT team and was elected to the DSA’s Board of Directors for his third term in January 2024.