A sergeant who oversees the activities of the area investigators as well as the school resource officers supervises the Lemon Grove Sheriff's Station Detective Division. This unit supports the patrol function at the station by responding to critical incidents, major crime scenes and by completing follow up investigations to original crime reports initiated by patrol deputies and community service officers.

When a citizen reports a crime, the first law enforcement officer to respond is usually a community service officer or deputy sheriff from the Patrol Diversion. These individuals conduct the preliminary investigation and file the initial crime report. Under normal circumstances, area detectives will be assigned to perform subsequent follow-up investigations.

Twelve of the thirteen investigators working out of the Lemon Grove Sheriff's Station are assigned geographic "beats" in the contract city of Lemon Grove or in the unincorporated areas of La Mesa, Spring Valley, Mt. Helix, Rancho San Diego, El Cajon and Jamul. One investigator is assigned to handle all auto-theft related incidents. Each of the four school resource officers is assigned to a specific high school in the Grossmont Union High School District.

As a general rule, homicides, arsons - explosive incidents, domestic violence incidents, child abuse incidents involving victims under fourteen years of age, complex fraud cases and some computer crimes are handled by specialized, centralized investigative units. The Lemon Grove Sheriff's Station detectives investigate cases involving theft, physical assaults, vandalism, burglaries, annoying telephone calls and all crimes not handled by the specialized units.

School Resource Officers handle all crimes relating to students at the high school level in the area serviced by the Lemon Grove Sheriff's Station. These crimes include truancy, tobacco, drug and alcohol related offences as well as other crimes that occur on school grounds.