RALEIGH, N.C. -- From April to October, while North Carolina farmers are planting, tending and harvesting their crops, hundreds of law enforcement officers across the state are engaged in the annual ritual of weed-pulling.
The Marijuana Eradication Program is a joint effort that uses federal funds, state-owned aircraft and county sheriff's officers to find and destroy marijuana plants. After more than three decades, investigators say, the program has helped bring about a change in the illicit industry: Local growers have begun to move their operations indoors, out of the sight of aerial spotters, leaving only tiny plots for pilots to search for in the verdant landscape.
When spotters do find a large crop, usually divided into parcels over several acres where the landowners are unaware of their presence, investigators think the plants are often being tended as part of an organized criminal effort.
"The trend has been toward smaller patches and better concealment, and there's a tremendous trend toward indoor growing," said Durb Turner, special agent in charge of the air wing of the State Bureau of Investigation.
Pilots for the SBI, the state Highway Patrol and the N.C. National Guard try to fly in each of the state's 100 counties at least once during the growing season. Marine Patrol aircraft also help with the work. They scan places where investigators have found pot in the past, as well as those where their detective work suggests it might be growing now.
It's an old-fashioned form of sleuthing that works best against a low-tech criminal.
"The easiest time to find it is when they first set the seedlings out in the spring," said Franklin County Sheriff's Detective William Mitchell, one of many local narcotics officers who have attended a state-sponsored "spotters school," where they learn to distinguish cannabis from kudzu at an altitude of 500 feet.
"[Growers] just go out and clear a space and put the seedlings in the ground," Mitchell said. "All you got to do is go up and look for the dots."
Aerial spotting is more challenging in late July, when the trees are full, milkweed is as tall as a house and a marijuana plant blends more easily with surrounding foliage.
Mitchell and more than a dozen other officers waited Wednesday morning at the Franklin County Airport for Highway Patrol helicopters to arrive. Crossing his tattooed arms, Mitchell said it was impossible to predict what they would find.
"We've got 497 square miles in this county," he said. "There's no way to fly it all. We know it [marijuana] is out there, but there's always going to be something you can't find."
Thirty years ago, Turner says, the biggest plots were usually planted by local growers. Some of those growers aged out of the business or just got tired of worrying they might get caught and lose their investment, Turner says. Some still raise a few plants, scattered over a broad area.
They have been followed, Turner thinks, by growers who have moved their production indoors, setting up elaborate greenhouse systems where high-quality plants can be raised year-round.
Investigators say those are more difficult to find. When plants are spotted outside on private property, law officers can move in immediately. But to raid a house, a search warrant is needed, and it's more difficult to establish the probable cause a judge or magistrate would require.
"They got to be out there," Turner said. "But if they're good at concealing it, we may never find out."
Plants worth millions
Last month in Harnett County and several times in recent years, investigators have found large plots totaling thousands of plants worth millions of dollars. They made arrests in one case and found evidence in two others, leading them to think crews were sent in from elsewhere and paid to raise those crops and bring them to harvest.
Police say both types of undercover agriculturalists are difficult to catch.
"Once they see us fly over, especially if we have to circle back to confirm, they're gone and they don't come back," said Lt. Todd Woodard, who oversees the aviation unit of the Highway Patrol.
In June, Woodard's group located a series of marijuana plots tucked in a remote, wooded area of Harnett County. At first, they estimated the crop to be about 35,000 plants. Investigators now say it was closer to 50,000, each with a street value of about $2,400.
Growers can slip away
The pilots were coordinating with ground crews of deputies, guardsmen and SBI agents staged at different areas of the county and ready to move in if the air crews found a stand of plants. When they swarmed into the area, they found the earth still damp where some of the plants had just been watered. But all they found of the growers were the meager shelters, clothing and food supplies they had hurriedly left behind.
Woodard's crews fly their missions from five bases across the state, in an aging fleet of military surplus OH-58 helicopters used for observation during the Vietnam War. His newest helicopter is 36 years old.
It costs about $340 an hour to fly the helicopters, which are used mostly for search and rescue and other functions. When they're flying for the marijuana eradication program, the SBI is reimbursed from an annual grant from the federal Drug Enforcement Agency. This year's grant was $290,000.