Two Modesto men are facing mandatory 20-year prison sentences after being convicted of running a medical-marijuana operation that federal prosecutors labeled a criminal enterprise, authorities said today.

Luke Anthony Scarmazzo, 28, and Ricardo Ruiz Montes, 28, were convicted by a federal jury Fresno on Thursday of conducting a continuing criminal enterprise, growing marijuana and possessing marijuana with the intent to distribute.

The conviction for running a criminal enterprise carries a mandatory sentence of at least 20 years. U.S. District Judge Oliver Wanger is to sentence both men Aug. 4.

Federal officials said the case sends a message to marijuana growers and dealers who believe they are shielded from prosecution under the California law legalizing medical marijuana use.

"Scarmazzo and Montes made millions by exploiting and hiding behind California's medical marijuana law," said McGregor Scott, U.S. attorney in Sacramento. "In this case, there was no conflict between state and federal law, as their conduct was illegal under both.

"California's medical marijuana law clearly sets out that making a profit selling marijuana is illegal," Scott said. "These two set out to make as much money as they could as drug dealers, plain and simple."

Scarmazzo and Montes obtained a business license from the city of Modesto by falsely representing that their California Healthcare Collective would engage in "retail sales of natural health-care products," authorities said. In reality, they limited their business to marijuana sales, authorities said.

The collective filed papers with Modesto stating that it earned more than $4.5 million while operating in the Central Valley city from 2004 to 2006, investigators said. But the evidence at trial showed that the defendants actually generated more than $9 million in sales.

Much of the money was used for personal purchases, such as Scarmazzo's $184,000 Mercedes-Benz, prosecutors said.

The jury found the men not guilty of possessing firearms in furtherance of a drug trafficking crimes. The panel could not reach a verdict on whether the men had conspired to distribute marijuana and possess marijuana with the intent to distribute.

Federal prosecutors are seeking forfeiture of more than $200,000 in seized assets.