When Palm Beach County sheriff's narcotics agents began looking into an indoor marijuana-growing operation last fall, they had no idea the case would lead to one of the largest rings taken down in recent years. As they investigated, the case got bigger and bigger, surprising even seasoned agents with its sophistication, high-quality product and mind-boggling profits. Federal prosecutors now calculate the loose-knit ring, which had been in operation since at least 1995, pulled in $8 million by growing potent strains of pot. Narcotics agents say the ring members were part of a new breed of marijuana growers. No longer are they cultivating large fields outdoors, where law enforcement helicopters buzz overhead, insects eat their fill, thieves help themselves, and Mother Nature provides less than ideal growing conditions. Instead, they went indoors, using exacting methods to control the crop and maximize their return. By following a formula, agents say, the Palm Beach County growers - who operated in cells allegedly set up by ringleaders - were guaranteed success. â€œThey had gotten it down to the McDonald's science of it. They would go in, set up a house, and move on to the next,â€ said Palm Beach Sheriff's Agent Richard McAfee. â€œThey knew what worked and what didn't. So long as you followed their ingredients, you were growing some phenomenal dope.â€ South Florida drug agents say they started seeing an increase in the number of indoor marijuana operations in the early 1990s. One reason: The U.S. Drug Enforcement Administration, the Florida Department of Law Enforcement and local agencies had been steadily busting more outdoor growers for more than a decade. And there was another reason the popularity of outdoor growing diminished: rapid development to the west. â€œWhen you take off in a plane from Miami or Fort Lauderdale, you are looking at a concrete jungle,â€ said FDLE Agent Rick Ward. â€œThe land is all taken out, and you've pushed them indoors.â€ Marijuana growers also learned they could better hide their crops indoors and get a stronger product that fetched far more money than that grown outdoors. â€œYou can grow a better product indoors,â€ said Broward County sheriff's narcotics Sgt. Joe Damiano. â€œYou have fewer pests to worry about, including law enforcement.â€ The growers often choose homes that are in isolated areas. But agents say they also have found grow houses in cramped apartments. The homes can be totally dedicated to the operation, with nearly every room put to use, but more often the garage or master bedroom is converted into the grow room. The growers do what it takes to avoid attracting attention. â€œThey fit in with mainstream society,â€ Damiano said. â€œThey mow their lawns. They will come home at dinner time, to make sure the neighbors see them.â€ One grow house in the historic Roads neighborhood in Miami was more than unusual. Police, acting on a tip about a funny odor coming from the two-story duplex, tried to question a man who came out of the house in January. He pushed an officer, ran back inside and disappeared. Police found 120 marijuana plants nourished by an elaborate hydroponics growing system - and a maze of shallow underground tunnels. The suspect got away but was arrested two weeks later. Numbers mixed Miami DEA spokesman Joe Kilmer said the number of arrests for indoor growing has gone up in recent years. â€œWe are simply seeing a great deal more of them. There is a pretty steady increase of them since the late 1990s,â€ he said. â€œIt is an extremely lucrative venture.â€ The number of outdoor marijuana plants eradicated last year was the lowest in the two decades the FDLE has been keeping records. There were 210 indoor operations busted, compared with 341 outdoor sites, according to the FDLE, with a total of 28,206 plants destroyed. FDLE statistics don't show a decisive trend in the number of indoor busts in the last 10 years. In 1989, there were eight. Three years later set the record that still stands, with 247 sites discovered. There have been about 200 indoor operations taken down in each of the past three years. But FDLE records show that virtually all of the arrests in South Florida last year came from indoor operations. Miami-Dade County led the state with 2,503 plants confiscated, and 49 of the 51 operations were indoors. Broward County's four operations uncovered were all indoors. In Palm Beach County, only one of the 11 operations discovered was outdoors. Palm Beach County has seen a spate of indoor operations this year, according to McAfee. â€œRight now off the top of my head, I can think of 10 that we have done this year,â€ he said. Potency increases There is a saying among narcotics agents. â€œI've heard this over and over - â€˜This is not the pot your daddy and momma had.' It's a more dangerous drug than was out there in the '60s,â€ said the FDLE's Ward. â€œThis is a more refined, higher-grade marijuana with higher THC levels.â€ Tetrahydrocannabinol, or THC, is the psychoactive component of marijuana that produces the â€œhigh.â€ The greater the level of THC, the more growers can charge for their crops on the street. Compared with ordinary marijuana grown outdoors or pot imported from Mexico, which fetches a few hundred dollars a pound, indoor marijuana can bring thousands of dollars a pound. â€œIt is a science to them. They will spend months and months reading material. It's also practice to get the perfect plant. It becomes art,â€ said Damiano of the Broward Sheriff's Office. Growers control the amount of light and nutrients given to the plants. They control the temperature. As a result, they have sped up the growth cycle so they can get four harvests a year, which means more profits compared with annual outdoor harvests. â€œPeople who went away [to prison] for years for cultivating, they came back and are caught again indoors,â€ Ward said. â€œYou ask them why, and they say, â€˜I can create a better product.'â€ In years past, THC levels were in the 2 percent to 3 percent range. Ward said today's indoor marijuana can reach THC levels of 7 percent to 10 percent. Buried fortunes The Palm Beach County growers busted this spring were producing such a refined product that it sold for $3,500 to $5,000 per pound, depending on the skills of the particular grower, agents say. The ringleaders allegedly presided over 13 grow houses scattered in isolated areas in the northern part of the county, according to federal court records. Prosecutors estimate each grow house could generate $400,000 a year. One woman arrested with a grow room sectioned off in a barn told agents she made $1.5 million in 18 months, according to records, although prosecutors haven't been able to find that money. She told agents she paid for a child's college tuition and bought a Harley-Davidson and a Dodge pickup with her profits. Agents are seeking to have those forfeited. Prosecutors were so concerned she would use her hidden profits to flee that they recently went into court and got a federal magistrate to revoke her bond. â€œIt's unusual for these types of cases,â€ said U.S. Magistrate Judge Linnea Johnson, remarking on how the case had expanded. The accused ringleaders hadn't held legitimate jobs in a decade, according to drug agents, who think their income came solely from growing marijuana. They bought property, a boat and houses with their money, agents say, adding they were so proficient that their pot sold at premium prices. â€œTheir pot was fetching $5,000 a pound. They were in it so long, it was just good, good quality,â€ McAfee said. In their back yards, agents dug up $2.2 million buried in taped-up Tupperware containers. They seized tens of thousands of dollars at other grow houses. â€œNobody knew what we were getting into in the beginning of this,â€ McAfee said. â€œThey're making so much money. You would never expect something like this in a grow case.â€"