The Detective Bureau performs a variety of tasks and assignments. Most of the Detective's caseload involves follow-up investigations arising from crime reports taken by patrol officers. However, Detectives often initiate an investigation from information received through other sources such as informants and concerned citizens.

Follow-up investigations commonly involve preparing search warrants and arrest warrants, surveillance, recovery of stolen property, and the preparation and presentation of reports to the Los Angeles County District Attorney’s Office for filing. Once a filing is obtained, Detectives work closely with a Deputy District Attorney to present the prosecution’s case before a judge and jury.