The Investigations Division and Crime Suppression Unit is overseen by Lieutenant Michael Brennan.
Lieutenant Brennan started his career as a police officer for the South San Francisco Police Department in March, 2000. In October 2003, Mike became a police officer with the Daly City Police Department. During his time as an officer, he served as an Agent with the San Mateo County Narcotics Task Force (SMCNTF), Task Force Officer with the Drug Enforcement Administration (DEA), Field Training Officer, K-9 Officer, and SWAT Team member. He was promoted to Sergeant in October 2012. During his five years as a sergeant, he was responsible for the direct supervision of patrol officers, became a SWAT Team Leader, supervised the Crime Suppression Unit and was assigned to the Bureau of Alcohol Tobacco and Firearms (ATF) as a Task Force Officer. In 2017, he was promoted to Lieutenant where he was assigned as the weekend Patrol Watch Commander overseeing all department operations and supervising numerous officers and sergeants assigned to his Division. In 2018, he was assigned as the Tactical Commander of the Daly City Police Department SWAT Team. In October 2019, Lieutenant Brennan was assigned as the Commander of the Investigations Division.