SAN DIEGO—A San Diego medical marijuana dispensary owner was sentenced Thursday to more than eight years in prison for conspiracy to distribute marijuana and other crimes, according to federal prosecutors.

U.S. Attorney Laura Duffy called Joshua Hester the "poster boy" for the types of marijuana dispensary operators the federal government is targeting for criminal investigation.

"He was a convicted drug trafficker making millions of dollars selling high-quality marijuana to recreational users and exploiting state laws that were meant to help the seriously ill," Duffy said after Hester was sentenced.

Hester sold the drugs at the Downtown Kush Lounge and Green Kross Collective, Duffy said. Together, the clubs had more than 2,500 members. Through federal wiretaps, Drug Enforcement Administration agents learned Hester was netting at least $10,000 a day at his pot shops.

Hester also admitted in federal court that he has a 37-acre Palomar Mountain property where he intended to grow marijuana.

Hester pleaded guilty to eight felonies Jan. 3. He was immediately taken into custody after sentencing.

About 253 dispensaries in San Diego and Imperial counties have received cease-and-desist letters from federal authorities. Duffy says all but about a dozen dispensaries have closed on their own.

Less than two weeks ago, San Diego's new mayor, Bob Filner, ordered local law enforcement and the city's prosecutor to back off of code enforcement of the city's remaining pot dispensaries.

Filner has assured residents that access to medical marijuana will be preserved and safeguards will keep the dispensaries away from children.