Mar. 16, 2010  -- Neither border crossings, nor sniffer dogs, nor extensive search efforts by authorities are keeping potheads from their appointed task: getting high.

According to U.S. government officials, more marijuana is now being shipped through the U.S. Mail than in recent memory. The U.S. Postal Inspection Service, whose seizures of marijuana parcels have increased by more than 400 percent since 2007, says increased seizures almost always indicate a much larger crop being shipped.

"There is no better way to ship drugs right now," said San Diego Police Chief William Lansdowne, whose city is one of the most popular in the country for using the mail to ship marijuana. "It's going up all the time."

Drugs are often concealed inside everyday items, like computer towers, car stereo amplifiers or microwaves.

Inspectors recently came across cans that appeared to be "Teasdale" canned corn. But when inspectors cracked the cans open, there wasn't corn inside. Instead, they found bags of marijuana. The smugglers heat sealed the drugs in bags, ensured the weight was the same as what was listed on the can, and used a can sealer to mask the smell.

The increase is a continuing trend. The total pounds of marijuana seized by inspectors, as well as the number of parcels containing the drug, have increased every fiscal year since 2005.

And postal inspectors, increasingly, have their hands full. There was an 84 percent increase in the amount of marijuana seized from 2007 to 2008 and a 180 percent increase between years 2008 and 2009. Inspectors uncovered 8,453 lbs. in 2007, 15,521 lbs. in 2008, and 43,403 lbs. of marijuana in 2009. In that same period, the total number of inspectors has remained relatively constant.

The U.S. Mail has always been an attractive way to ship pot, authorities say. It is seen by drug dealers as a good alternative to having someone drive a shipment cross-country, where one risks arrest and loss of product if stopped by law enforcement. However, the recent spike in marijuana mailings can also be explained by increased demand for the drug and by inspectors improving law enforcement techniques.

Now, inspectors are working to determine which mailboxes are attractive targets for traffickers.

Targeting 'Hot beds' for Shipping Marijuana

They have become more efficient in what's known as ZIP Code targeting, said Peter R. Rendina, a postal inspector and national spokesperson for the U.S. Postal Inspection Service. Through the course of investigations, inspectors identified which mail centers see the most drugs. Inspectors from other geographical locations are sent to assist those mail centers until problem becomes more manageable.

"Right now, we're really seeing an uptick in drugs being shipped through the southwest to destinations throughout the U.S.," said Rendina.

Of the 3,621 parcels of marijuana intercepted by inspectors nationwide in 2009, 75 percent were in the border towns of Texas, New Mexico, Arizona, and California. The area is seen as a "hotbed" for using the Postal Service to transport marijuana.

While post offices in the southwest region have seen the most drugs come through, other parts of the U.S. aren't immune. Last month, a New Jersey man was arrested for allegedly purchasing methamphetamine in California and mailing it to Newark, N.J. After obtaining a search warrant for the parcel, inspectors say they found 300 grams of meth inside. The case is still pending.

Illegal drugs are also being shipped to the Midwest. In the rural stretches of north-central South Dakota, a woman was expecting a new television at her home in Walworth County. When a large box was delivered to her doorstep, she assumed the television had arrived. Instead of finding a television inside the box, she found three bricks of marijuana, totaling 50 lbs.

"It was not what she expected," said Sheriff Duane Mohr, who believes a Mexican drug cartel sent the package to the wrong address. "It had an international post stamp on it, but they were crafty enough to print off a return address label with a Motorola logo on it just to make it look legitimate."

Mohr estimates the drugs had a street value of $100,000.

Why Mailing Marijuana is Attractive

There are 1,614 inspectors at mail centers across the country looking for suspicious packages. Every day, they comb through the thousands of pieces of mail. Many inspectors employ the help of canine teams to locate packages containing drugs, though parcels are often packed with mustard, peanut butter, axel grease or coffee beans to cover up the drugs' odor.

There is "an attraction to shipping through the mail because they think they can be anonymous," said Rendina.

Rendina explained that drug cartels believe there is less risk in having a mule drop off a package at the post office, instead of driving a U-Haul full of product across the country.

But arrests are happening. In 2009, 1,278 people were busted for using the mail to transport drugs.

To identify potential suspects, inspectors conduct interviews, review video surveillance, and examine paper trails, like when and where the package is scanned. Inspectors also use intelligence about drug cartels and analyze drug trafficking trends, which they obtain on their own or by working with other federal law enforcement agencies, like the U.S. DEA.

Inspectors offer a $50,000 reward for information leading to the arrest and conviction of individuals shipping illegal substances through the U.S. Mail. Rendina says the reward money comes from asset forfeiture.

While marijuana mailings have increased, shipments of other drugs have declined. Between fiscal years 2008 and 2009, there were fewer seizures of cocaine, heroin, opium, and methamphetamine.

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