The Investigation Bureau consists of full-time peace officers, known as District Attorney Investigators, who work daily to protect the citizens of Sutter County and assist in the prosecution of cases. The bureau also includes Investigative Aides who process discovery and evidence, locate witnesses, and serve subpoenas. Sutter County District Attorney Investigators assist local law enforcement agencies and task forces with investigations, search warrants, wire taps, and investigate officer-involved shootings. District Attorney Investigators also conduct background investigations, independent criminal investigations, and public integrity investigations.

District Attorney Investigators are classified under California Penal Code section 830.1 to the same extent as municipal police officers, deputy sheriffs and deputy marshals.  Sutter County District Attorney Investigators are charged with day-to-day police protection and maintenance of order throughout the County of Sutter and possess arresting authority within the State of California.