Special Investigations Section
- Arizona Attorney General
- Atlantic City Police Department
- Baltimore Police Department
- Criminal Investigation Department (Singapore)
- Delaware State Police
- Halifax Regional Police
- Indiana State Police
- Indianapolis Metropolitan Police Department
- Kentucky State Police
- LAPD Special Investigation Section
- Las Vegas Metropolitan Police Department
- Metro Vancouver Transit Police
- Miami Gardens Police Department
- Miami Police Department
- Michigan State Police
- New Jersey State Police
- Office of Special Investigations (disambiguation)
- Rochester Police Department
- SIS (disambiguation)
- Sarasota County Sheriff's Office
- Special Investigation Team
- Special Investigation Team (India)
- Special Investigations (disambiguation)
- Special Investigations Bureau (disambiguation)
- Special Investigations Division (disambiguation)
- Special Investigations Unit (disambiguation)
- State bureau of investigation
- State police (United States)
- Tennessee Department of Revenue
- Tucson Police Department
- Vancouver Police Department
- Washington State Patrol