Mexican drug cartels have stepped up the pressure and are attempting to smuggle narcotics into the United States in alarming numbers and in increasingly creative ways.
From methamphetamine stuffed inside a car battery, to black-tar heroin wedged in a drive shaft, to fuel tanks filled with drugs instead of gas, the cartels are going to great lengths to get their narcotics into the U.S., law enforcement officials say.
Smuggling is nothing new here, yet the sheer volume is surprising.
In just one hour at the San Ysidro Port of Entry, we watched U.S. Customs and Border Protection agents seize more than $250,000 in hardcore drugs, and that's not counting what hadn't yet been found lined inside a SUV.
While showing us a drive train pulled from a newer Ford pickup, Chris Maston, U.S. Customs and Border Protection's San Diego director of field operations, told us, "The trend seems to be much deeper concealments, much more difficult to detect, and this is a real good example of that. This came in this morning ... We got 14 pounds of Mexican tar heroin out of this drive shaft."
Agents here at one of the U.S.'s busiest ports of entry say that they've seen a 70 percent increase in cocaine smuggling, 40 percent in heroin and 20 percent in methamphetamine. On any given day, more than 90,000 people legally enter the United States here, and while the great majority are law-abiding, drug cartels are trying their best to scatter smugglers among them.
"These are significant increases. We have to make sure that we are throwing up every barrier we can out here without choking off legitimate trade and travel, and that's the difficult part of our job," Maston said.
Dog teams weave across the lanes as drivers heading north idle for several hours awaiting their turn. We watch as one young woman in her mid-20s gets asked to pull over. She parks in a secondary inspection area, and, as the dog passes the driver's side of her SUV, he gets a whiff of the cartel problem.
Within two minutes she is being led away in cuffs, and the dog literally attacks the lining inside the driver's door. An agent then carefully peels back the cloth to reveal a stash that has been neatly concealed in hopes of making it pass inspectors. This time, though, the game is up.
When you overlook this point of entry, it is impossible to try and figure out which car to look might have black tar heroin stuffed inside. The task seems impossible, but that does not deter agents, who use the dog teams, gather intelligence and in some cases just observe human behavior.
While agents are making significant busts here, increased hardcore smuggling by the cartels means more black-tar heroin, methamphetamine and cocaine are widely available on the streets, and local law enforcement are seeing increasing numbers of teenagers using the drugs.
"There are more seizures of the harder drugs coming from Mexico, and of course the affects of what that means for law enforcement and the challenges that we face going forward. Not just in a smuggling perspective, but for a quality of life in the communities," San Diego Sheriff Capt. Dave Myers said.
Myers also said the recent decriminalization of drugs on the south side of the border has made their job even more difficult. He says they see marijuana as an entry drug, and its numbers are up just like hardcore drugs.
According to the latest numbers, marijuana seizures in the San Diego sector have already tripled their 2010 levels, at 65,189 pounds. The San Diego Border Patrol has also seized 1,368 pounds of cocaine, already topping the total for all of 2010.
Even with what seems as an insurmountable odds, the agents are unwilling to give in and the seizure numbers show that they are making a dent in cartel business.
As one agent tells me, "if it gets past us here, it immediately scatters across the U.S., and it's our job not to let that happen."
Adam Housley joined Fox News Channel (FNC) in 2001 and currently serves as a Los Angeles-based senior correspondent.