Chief Thomas Chaplin (Ret.)


Thomas Chaplin is a retired law enforcement professional with over 32 years of service. He is a principal owner and partner of Chaplin and Hill Investigative Services which performs workplace investigations and consultation for agencies in California. He serves as adjunct faculty for the University of San Diego where he teaches the graduate courses Organizational Theory and Change, Public Safety law, and Contemporary Issues in Criminal Justice. He teaches undergraduate courses for National University including Criminology, Ethics and the Criminal Justice System, and Intro to Police Services. He has developed courses and provided instruction for the California Police Chiefs Association to include Advanced Role of the Police Chief and Partnering for Success – A Course for Seconds in Command.

Chief Chaplin served as a governor appointed commissioner for the California Commission on Peace Officers Standards and Training (POST) (2016-2019). He was on the board of directors for the California Police Chiefs Association (2013-2020), where he served as chair of the Training Committee. He served as chair of the Contra Costa County Police Chiefs Association (2020). He is the course coordinator for the California POST Executive Development Course.

Chief Chaplin served as the police chief for the city of Walnut Creek, California from July 2013 until his retirement in October 2020. Prior to his appointment, he served with the Citrus Heights, California, Police Department as a lieutenant and later commander in the Patrol Division and the Investigative Services Division. In addition to being a member of the department start-up team, he spent nine months in the role of deputy chief of police. Chief Chaplin incorporated and served as president of the Citrus Heights Police Activities League.

Chief Chaplin spent five years with the California Department of Justice, where he was assigned as special agent on the Sexual Predator Apprehension Team, California Bureau of Investigation, Sacramento Regional Office; special agent supervisor for the Investigative Support Team – California Attorney General’s Office – Northern California; and special agent in charge for the Mission Support Branch, overseeing the Professional Standards Group (Internal Affairs), Background Investigations Unit, and Litigation Unit.

Chief Chaplin started his law enforcement career with the Sacramento, California, Police Department. There he served as a community services officer, patrol officer, field training officer, neighborhood police officer, and detective. He was instructor at the police academy for the LD-12: Controlled Substances.

Chief Chaplin holds a bachelor’s degree in Occupational Studies and a master’s degree in Emergency Services Administration, both from California State University, Long Beach. He is a graduate of the 44th class of the California Command College.