The tip identifying the drop house allows the Nogales (Ariz.) Police Department's K-9 unit to move in. Once the dog gets the hit and relays its scratch alert on the door, officers begin swarming the property.

The officers converge on the house. It's nondescript in a way that only a drug house can be. The front yard is clumps of crabgrass and swaths of dirt. There are no children's toys, potted plants, or the other signs of life that you see in front of a home. The residents have pulled off the address numbers and black curtains line the inside of front-facing windows to block curious eyes. This is a staging area for narcotic loads waiting to move north into the heart of America.

The officers have a search warrant. They line up at the front door with a handheld ram. "Hello. Police. Open the door. 

"Policia. Abra la puerta. Orden de cateo."

No answer. The officers repeat the commands. Again, no answer. After a third set of commands, they pop the door. The pungent odor of weed wafts out of the building but the suspects have fled, leaving officers only a few 25-pound bundles to book into evidence.

Symbiosis

Stash-house raids such as this one are routine here in Nogales, a border town of some 20,000 people situated in the rolling hills of the Sonoran Desert. For in reality, Nogales is two towns in one. A metal fence divides Nogales, USA from another Nogales: Nogales, Sonora, a much poorer Nogales where law enforcement is under attack from drug trafficking cartels and the cartels are under attack from many rivals.

Nogales is a flashpoint in the drug war, in the campaign against human trafficking, and in the politics of immigration. All of these problems stem from its proximity to Mexico, but like many border towns, Nogales also lives in a symbiotic relationship with its neighbor.

As in El Paso; Laredo, Texas; Pinal County, Ariz.; and other smuggling hot zones along the 1,951-mile border, Nogales is a commercial gateway for many legitimate commodities such as watermelons and tomatoes, as well as marijuana, meth, cocaine, and heroin.

The dependency that the locals have on legitimate trade with Mexico makes life complicated for the law enforcement officers who work the Nogales area. And that includes the 65 sworn officers of the Nogales PD who daily interdict smugglers on vehicle stops, on foot, and in the city's storm-water drainage channels.

Violent crime is not very common in Nogales. There hasn't been a murder in three years, but the threat of cartel violence is palpable. And as the Nogales PD takes a more active role in multi-agency task forces, cracking down on stash houses, and seizing larger narcotic loads from Mexico, some fear that the cartels may coil out and strike like an angry rattlesnake uncovered under a rock by a rancher.

South of the fence in Sonora, violence is all too common. The cartels racked up 130 murders during the first half of this year, as Joaquin "El Chapo" Guzman's Sinaloa Cartel and the Beltran-Leyva Cartel warred for control of the smuggling routes. Also, the paramilitary Los Zetas cartel operates across the border using counter-surveillance, assault vehicles, and even car bombs to intimidate police and exert control.

The officers of the Nogales Police Department work on the edge of this multi-faction cartel war. And sometimes they feel its impact.

A criminal informant recently passed along a cartel message that Nogales officers who seize narcotics while off duty would be marked for death. The threat came after officers snared 400 pounds of marijuana while riding horses on ranchland east of town. The note specifically warned officers not to cross the cartel off duty, saying that doing the job while on the clock was understood but off-duty enforcement would be punished.[PAGEBREAK]

Would the cartels really declare war on American police officers like they have in Mexico? The answer is unclear, but they have proven in the past that they will do anything to protect their business.

Vague Stories

And despite America's Great Recession business is booming.

The Department of Justice's 2010 National Drug Threat Assessment estimated Mexican cartels receive $39 billion from drug trafficking. When those drugs reach the streets of Los Angeles, Chicago, Atlanta, and other U.S. cities, they fetch as much as $200 billion.

On the Arizona border cartel suppliers are trying to keep up with the American public's demand for getting high and cops are doing their best to stem the flow.

Because of local and federal law enforcement efforts, drug seizures have been spiking. Nogales PD is part of that coordinated effort. From January to June of this year, the department seized more than 15,000 pounds of marijuana, compared to 10,000 and 11,000 pounds the prior two years. In the late 1990s, the department seized about 1,000 pounds a year.

With so much emphasis on drug seizures, the department relies heavily on its K-9 officers. Officer Amador Vasquez and his K-9 named Illo, a Czechoslovakian-trained German shepherd that responds only to Czech commands, assist patrol units on highway interdiction calls.

"Once we have probable cause, we make contact with the driver," Vasquez says. "Whether we use the K-9 is based on the story the driver gives us."

Narcotic transporters usually tell vague stories that they're searching for a friend-they can't remember the friend's address-or that they're "going to play soccer" without sporting equipment or gear.

Drugs are concealed in crevices of SUVs, pickup trucks, and passenger cars. Tractor trailers bring contraband hidden with a "cover load" of vegetables or watermelon.

Regardless of what stories the drivers tell or where the drugs are hidden, the Nogales PD has a record of finding them. And when they do find them, the department can benefit from vehicle forfeitures and cash seizures. Thirty-five transporter vehicles have brought almost $150,000 in asset forfeiture funds.

Unfortunately, drug smugglers can be very creative. So when vehicles come under suspicion, they find other means for getting their product into the country.

Some have even gone so far as to send the drugs in with sewage. Tightly wrapped packages have been floated through the International Outfall Interceptor (known as the IOI), a common sewage pipe that delivers wastewater from Nogales, Sonora, to the Nogales International Wastewater Treatment Plant six miles north of the border in Rio Rico, Ariz.

The drugs get in through a variety of means and, despite the best efforts of law enforcement, they then have to be warehoused until transporters can take them to U.S. cities. The houses used for this purpose are often rentals.[PAGEBREAK]

To address this, Nogales Police Chief Jeffrey Kirkham introduced a "crime free" certification program shortly after his arrival for property owners who implement CPTED (crime prevention through environmental design) measures, agree to regular inspections, and accept agency training on rental agreements and liability issues.

Eyes Across the Border

In the rugged ranch country east of town, officers may come into contact with armed smugglers ferrying narcotic loads across a passageway of canyons and hills with nicknames such as Hamburger Hill or Frankenstein Hill that lead to State Route 19 and the Nogales Airport.

It's up in these hills where a group of off-duty officers on horseback seized dope bundles and arrested cartel transporters back in June. After the seizure, criminal informants in Mexico relayed the threats from the cartels that additional busts would bring assaults on officers or sniper fire from the higher ground rising above the south side of the border fence.

As a result, Chief Kirkham issued a directive that his officers must wear body armor and carry a police radio if heading to the area off duty. Patrols in certain areas of the city are off-limits; in other areas, solo-officer patrols aren't permitted.

"You do adjust your habits," says Assistant Chief Roy Bermudez, who has also curtailed his visits to rodeo contests and other off-duty recreational venues. "That's part of the cost of doing business. You learn to shy away from those positions."

Southern Arizona law enforcement officers say the cartels are primarily interested in an uninterrupted flow of contraband rather than the killing of officers. But the officers know that they are always being watched by eyes across the border. In the smuggling corridor, cartel lookouts radio the locations of officers, Kirkham says.

"They're always watching us," Kirkham says. "They tell their scouts how to avoid us. The war zone is south of here. But the potential is there for it to hop over the border." 

Not Backing Down

Despite threats from some of the most deadly and ruthless criminals in the world, Kirkham says he is determined to hold his ground against the smugglers.

Unfortunately, he can't always count on adequate equipment, support, or facilities.

Kirkham took over the department in January with 25 years of experience in Arizona agencies, including assignments as a Maricopa County Sheriff's deputy, Mesa PD officer and lieutenant, and member of the Pinal County Sheriff's command staff.

Coming into the job, he believed that he could find money to improve the department. He still does, but he now knows it probably won't be coming from federal sources.

So far, Kirkham's attempts to gain federal grant funding for a modern police facility to better protect and secure his officers have fallen on deaf ears in D.C.

At the existing headquarters, visitors come and go as they please, pulling into an open driveway that leads back to parking lots with the cruisers, motorcycles, and other patrol vehicles. The lack of access control is apparent. Open lots and driveways lack fencing, surveillance cameras, and keycard entry control.

The physical facilities aren't much more evolved. The town's judge signs search warrants out of a closet-sized office under a City Hall stairwell. The department uses former holding cells as its evidence storage. This day, Cell Block C is filled almost to the ceiling with bundles of marijuana, bags of meth, and bricks of cocaine.

Kirkham has even appealed for funding to Homeland Security Director Janet Napolitano, Arizona's former governor. "I've sent her personal letters," Kirkham said. "To date, I've heard no response. If they (the drug cartels) are going to target officers, we're wide open."

Kirkham will next turn to the Tohono O'odham (T.O.) Nation Native American tribe's public safety grant program. A portion of the tribe's gaming proceeds fund local projects.

Related:

Combating Human Smuggling

VIDEO: Drug Cartel Threatens Arizona Officers