Most investigations are handled by this Division.  Stanislaus Drug Enforcement Agents work under the Investigations Bureau.

When cases need timely and extensive follow-up, the Investigative Services Division takes the case. For example, all homicides and major felonies are investigated here.

There are further specialized detectives and officers formed into additional investigative units

• Crimes against persons 

• Economic crime unit

• Special Victims Unit (crime against children, domestic violence)

• Property Crimes

• Gang Unit
  
• Modesto Narcotics Enforcement Team