Special Investigations Unit (SIU)

The Nevada County Sheriff Special Investigations Unit (SIU) is a multi-agency unit supervised by the Sheriff’s Office. If you have any information regarding illegal drug / narcotic activity please contact the confidential Narcotic Tip Hotline at 530-265-1699.

Funding & Responsibilities


The SIU receives funding from various state and federal grants. Each member of the unit must complete many hours of training in a variety of areas including (but not limited to) drug laws, drug recognition and identification, drug composition, search warrant policies and procedures, surveillance and evidence collection. The SIU is responsible for investigating information regarding narcotics trafficking, the manufacturing of controlled substances and the cultivation of illegal marijuana (indoor and outdoor grows).

Marijuana Cultivation Signs


With indoor marijuana cultivation rising, the SIU would like to educate the public on a few signs that may be an indication that your neighbor is cultivating marijuana within their home. Indoor grows are found in all types of neighborhoods.

Signs may include:
  • Air-conditioning unit continuously running, day and night, even when outside temperature is cool
  • Bright light or glowing from windows
  • Buzzing or humming sound from light ballasts
  • Carbon dioxide tanks
  • Garage doors never opened
  • No furniture brought to location
  • No one living at residence
  • Obvious modifications to electrical panels
  • Odor of marijuana
  • Portable air-conditioning units
  • Remodeling or demolition as soon as subjects move in
  • Roll-up garage door with the windows covered
  • Sound of attic exhaust fans running
  • Subjects have little or no contact with neighbors
  • Windows covered / sealed, blinds, window coverings
  • Yards maintained to avoid suspicion