June 24, 2010 -- A Mexican drug cartel has threatened police officers in Arizona who confiscated a marijuana shipment, prompting the small town department to warn its officers to remain armed and have radios with them at all times, and keep their body armor handy.
Police and experts believe the warning against the Nogales, Ariz., cops marks the first time that powerful Mexican drug cartels, used to bribing and bullying police south of the border, have targeted U.S. officers.
Jeffrey Kirkham, chief of the Nogales police department, told ABCNews.com that informants had delivered the threats after two off-duty police officers seized 400 pounds of marijuana while horseback riding outside the city earlier this month. The pot was worth about $250,000, he said.
Kirkham said informants have told his police department that off-duty officers should ignore cross-border drug shipments or face retaliation.
The threats appear credible because various informants were able to identify the officers who intercepted the drug load. Kirkham said the threats by Mexican traffickers were the first against local law enforcement on the U.S. side of the border.
"They're getting upset that their product so to speak is not getting to where it needs to be," Kirkham said of the cartels.
The chief said he gave a stern warning of his own to his 63 officers for what to do while they are off duty.
"We met with all the employees and supervisors to make them aware of what was said, and to make sure that they have their body armor and are armed and that their communications equipment is working properly," Kirkham said.
Kirkham attributed the surprising threat toMexico's war on the cartels.
"The pressure is on them from the president in Mexico and that desperation is starting to spill over the border," Kirkham told ABCNews.com.
Attacks by Mexican cartels on American law enforcement officers would be an alarming escalation of the Mexican drug wars. Cartel turf wars have killed more than 23,000 people across Mexico since President Felipe Calderon launched a military crackdown on drug gangs in late 2006.
In the neighboring Mexican city of Nogales, attacks on police officers have become commonplace. A deputy police chief in Nogales, Mexico, and his bodyguard were shot dead in March when gunmen in a pickup truck opened fire on them with assault rifles.
In November 2008, the police chief for Sonora state, which includes Nogales, was ambushed and killed just a few miles south of the Arizona border.
Sinaloa Cartel May Be Responsible for Threat to U.S. Cops
The Nogales police department has been hit hard by budget cuts recently, but Kirkham said the U.S. Border Patrol has sent additional agents to the area.
"I take these recent threats seriously," said George Grayson, a professor at the College of William & Mary and an expert on Mexican politics. "These cartels have such firepower and have so many cadres that if you're on the wrong side, you're life is certainly in danger."
Grayson said the threat likely came from the Sinaloa Cartel, which is headed by Joaquin "El Chapo" Guzman, who is being sought by American and Mexican authorities. The U.S. State Department is offering a $5 million reward for information leading to his arrest.
"The cartels are more likely to go after local police," Grayson said. "You threaten an FBI agent and it does sound alarm bells across Washington. The same with Drug Enforcement Administration."
Phil Jordan, former DEA intelligence chief along the U.S.-Mexico border, believes Guzman may have been behind the threats in order to divert law enforcement attention away from the heavily-travelled drug corridor between El Paso, Texas, and Juarez, Mexico. But he doesn't think Mexican cartels will actually target American law enforcement.
"Let me tell you something about the cartels – whether they're from Colombia or Mexico or Russia – they do not under any circumstances want to spend time in American jails," Jordan told ABCNews.com. "The cartels are not going to take us on on American soil. They have cells all over the U.S. but they don't want that type of attention."
Jordan added, "Chapo Guzman is no dummy. If he can put out stuff like that so we can send reinforcements to the Nogales sector, he knows we'll have to send people from the Texas border to help and you'll see an increase in drug loads moving through Texas."
The Los Zetas criminal organization, the Sinaloa Cartel's chief rival, had previously operated in the Nogales area, but Grayson said Guzman has probably taken over control of operations there in recent months.
"El Chapo has really enjoyed a comeback in the last several months," Grayson said. "These threats are just a general flexing of the muscles by the cartels. El Chapo has to be emboldened by the fact that Los Zetas find themselves on the defensive."
The Sinaloa Cartel is one of the biggest suppliers of cocaine to the United States. Its members are well-trained and well-armed, according to experts. About 90 percent of all the cocaine consumed in the United States passes across the Mexican border.
The booming drug trade has fueled powerful drug armies willing to take on Mexican police and even the army, and have no qualms about terrorizing civilians as well.
In the northern Mexican state of Sonora, across the border from Arizona, 126 drug-related homicides have been reported so far this year.
Mexican Drug Cartels Deadly Legacy
This week, with more than 40 deaths attributed to drug violence, including 12 federal police officers ambushed on Monday.
Last week, gunmen killed 16 people in Ciudad Madero, and 19 men were shot dead at a drug rehab center in Chihuahua.
Across the border from El Paso, Texas, in Ciudad Juarez, the body count has soared to nearly 1,200 this year. An estimated 2,700 were killed in 2009, a number that neared that year's death count for civilians and U.S. and coalition soldiers in Afghanistan, according to the United Nations.
"The cartels are feeling their oats now," Grayson said.