Officials with the Santa Clara County sheriff's office arrested 48-year-old Juan Carrillo after serving a search warrant at his home in San Jose.
Investigators believe he allowed several known criminals to live at his home in exchange for free, illegal drugs.
Officials say Carrillo was arrested for being under the influence of a controlled sustenance and in possession of a controlled substance.
Three others were arrested along with Carrillo on drug possession charges.
Carrillo has been with the Santa Clara Sheriff's Office for 14 years. He's been placed on administrative leave and is being held on $121,000 bail.
Anyone with information on this case is being asked to contact the Santa Clara County Jail Investigations Unit or Internal Affairs Unit at (408) 808-4500 or the anonymous tip line at (408) 808-4431.