Officials said an elaborate marijuana growing site was found in an industrial building 25 feet from the back door of the Topanga police station in Los Angeles, and three people are under arrest. Officer Karen Rayner said the pot was discovered Wednesday when a search warrant was served at an address adjacent to the station in Canoga Park.

The indoor marijuana farm included lights, automated irrigation and a ventilation system. Investigators said it had been there for at least eight months.

The investigation began a week ago, when officers smelled marijuana in the police station parking lot.

The suspects’ names have not been released. Rayner says they face a number of narcotics charges.