SACRAMENTO, Calif. (AP) - Federal authorities in California announced charges Thursday against 18 people they said operated a lucrative marijuana-growing operation by converting Central Valley homes into high-tech pot nurseries.
They estimated the value of the marijuana crop at nearly $100 million a year.
All the suspects are from the San Francisco Bay area, but half remain at large, including several who authorities believe fled to China or Hong Kong.
Nine were arrested early Thursday on drug and real estate fraud charges. All but one of them made initial court appearances later in the day. The remaining suspect already is in federal prison in California on unrelated charges.
Thursday's actions brought to 34 the number of people who have been charged in an investigation dating to 2006 and 2007. Law enforcement agents previously discovered about 24,500 marijuana plants growing inside 51 converted homes in Sacramento, Elk Grove, Lathrop, Modesto, Stockton and Tracy.
The operation would have produced nearly 11 tons of high-grade marijuana each year with an estimated street value of
$96 million, said Gordon Taylor, who heads the U.S. Drug Enforcement Administration's Central Valley office.
He said the ring was one of the largest and most sophisticated indoor marijuana growing operations in the nation.
Prosecutors said the growers bought homes for between $400,000 and $600,000, most in subdivisions that were new or a few years old. They knocked out interior walls, installed expensive ventilation and hydration equipment, and tapped power lines to grow thousands of plants.
Agents said the growing systems alone cost tens of thousands of dollars for each home.
Taylor called it "one of the largest, most sophisticated residential indoor marijuana growing operations in U.S. history."
"They came into our cookie-cutter residential neighborhoods and created cookie-cutter marijuana factories," Taylor said at a news conference. "It affected the real estate, mortgage and utility company industries, not to mention the stigma it placed on the neighborhoods where hardworking people worked for years to save up enough money to buy one of these nice homes."
He said the operation was connected to organized crime but would not elaborate.
Officer Chris Trim of the Elk Grove Police Department south of Sacramento said it took federal agents and Internal Revenue Service investigators several years to work their way up the chain and through real estate documents.
"They were able to track down those persons that were directly responsible," he said.
After the initial raids in 2006 and 2007, federal authorities charged 17 lower-level operatives they described as gardeners and caretakers. Fifteen have pleaded guilty, while two remain fugitives.
The charges brought Thursday targeted those who prosecutors believe orchestrated the operation.