Thomas Grossi Sr. has been many things, from a pawnshop owner to a decorated helicopter pilot in the Vietnam War, but it was his ownership of warehouses that got him in trouble with the law. He has maintained that the marijuana grown in these Oakland properties was destined for northern California dispensaries, where it would be distributed to medical marijuana patients. That claim didn't matter to the Drug Enforcement Administration, who was called in to investigate after the California Highway Patrol discovered 2,379 marijuana plants at one of Grossi's properties in June 2004. A federal indictment followed in February 2005, and the case went to trial in January 2006. The jury convicted Grossi for making one of his properties available to another person for the purpose of unlawfully manufacturing marijuana.

The jury deadlocked on counts related to another location owned by Grossi, but shortly afterwards he made a plea agreement in which he admitted to these charges as well as to managing a third location where marijuana was grown. At sentencing in May 2007, the defense attorney emphasized that Grossi merely allowed the cultivation and that he "didn't proactively decide to grow marijuana." Nonetheless, Grossi was sentenced to 30 months of incarceration and ordered to forfeit approximately $396,000.  After serving his time at Lompoc, he was released from prison in the summer of 2009.

Police gave conflicting accounts of the June 2004 raid; the CHP says it called on the DEA after Oakland police declined to help. Two defendants pled and received misdemeanor probation: Jacek Mroz, 27, of San Leandro, and Jesse Nieblas, 31, of Alameda. Also arrested were Mario Pacetti, 33, of Alameda, Heleno Araujo, 32, of Concord, and Celeste Angello, 28, of Santa Clara. Angello was sentenced to 2 years probation and Araujo pled guilty to a misdemeanor charge of maintaining a place for manufacture of marijuana. Pacetti pled guilty in February 2005 and was sentenced to one year and one day in prison on March 8, 2007.  Alleged grower Roy Lewis, 52, was also indicted with Grossi, convicted, and sentenced to probation due to ill health in April 2007.