Law enforcement officers in west Texas are on guard following an alert issued by the Department of Homeland Security warning of retaliatory killings for a recent crackdown on the Barrio Azteca gang.
David Cuthbertson, special agent in charge of the FBI's El Paso division, said the paramilitary-style gang has an "open policy" to kill its rivals and may turn its sights toward local law enforcement officers.
"[They] are extremely cold-blooded and aggressive," Cuthbertson told FoxNews.com. "The killings are done really without thought and any kind of remorse."
Citing uncorroborated information, Homeland Security issued an Officer Safety Alert on March 22, advising lawmen in the El Paso sector to vary their routes to and from work and to wear body armor while on duty. The alert also suggested that officers' relatives pay closer attention to unusual activity in the area.
"The Barrio Azteca gang may issue a 'green light' authorizing the attempted murder of [law enforcement officers] in the El Paso area," the alert read. "Due to the threat, it is recommended that [law enforcement officers] take extra safety precautions."
The Barrio Azteca gang, which formed in Texas prisons in the 1980s, is a brother organization to the Aztecas gang in Ciudad Juarez, Mexico, the epicenter of Mexico's violent drug war, Cuthbertson said.
He said members of the gang's "assassination teams" are thought to work for very small monthly fees. One official from the Drug Enforcement Administration has said Aztecas have been known to kill for as little as $100. Since 2006, drug violence across Mexico has claimed nearly 18,000 lives.
Eduardo "Tablas" Ravelo, the reputed boss of Barrio Azteca members living in Juarez, remains on the FBI's Ten Most Wanted List, and the FBI is offering a reward of up to $100,000 for information leading to his arrest. He and other Barrio Azteca gang members serve as hitmen for the Vicente Carrillo Fuentes drug trafficking organization -- also known as the Juarez cartel -- and are responsible for several killings, according to the FBI.
The DHS warning came just days after hundreds of Barrio Azteca gang members were interviewed by officials from the Drug Enforcement Administration (DEA) and FBI following the murders of three people linked to the U.S. Consulate in Ciudad Juarez on March 13. More than 200 officers from at least 18 agencies participated in "Operation Knockdown," which resulted in at least 26 felony arrests of alleged Azteca members.
The Barrio Aztecas are believed to be aligned with the Juarez cartel against the Sinaloa drug cartel for control of the billion-dollar drug-trafficking routes through the El Paso-Ciudad Juarez corridor. Since 2008, the Aztecas have been rivals of the Artistic Assassins, or "Double A's," who serve as contract killers for the Sinaloa cartel, Cuthbertson said.
"They're very organized," he said. "They have a code they go by and certainly a communication network inside and outside of the prison system."
Cuthbertson said Barrio Azteca gang members have been found in central Texas towns like Odessa and Midland, as well as in southern New Mexico.
Ricardo Valles de la Rosa, an Azteca sergeant, said last week in a purported confession that his gang was hunting for the vehicle of a Texas jail guard who was killed in one of two SUVs attacked in the March 13 shootings that killed El Paso jail officer Arthur Redelfs, his wife Lesley Enriquez, who worked as an employee of the U.S. consulate in Ciudad Juarez, and Jorge Alberto Salcido, the husband of another consulate worker.
Valles de la Rosa, according to his statement, was instructed by Azteca brass to target Redelfs due to alleged harsh treatment of Azteca members in jail. Valles de la Rosa was ordered last week to be held for trial on weapons charges for allegedly carrying a 9mm pistol when he was arrested.
Ron Martin, president of the El Paso Municipal Police Officers' Association, said that while he takes any threat to the law enforcement community seriously, he won't change his habits.
"It's not the first time a gang has put a hit out on El Paso police officers," Martin said. "Our guys are very highly trained, so they're pretty well prepared for just about anything. For them to come out and attack a law enforcement officer in the United States would be detrimental to their business."
Martin called the March 13 killings "unacceptable" and said he felt the killings were no less shocking because they occurred in Mexico, just across the border, rather than in El Paso or elsewhere in Texas.
"It doesn't matter if it actually happens across an imaginary dotted line, you're killing people for money," he said. "It's unacceptable."
Asked if he had changed his daily routines since the DHS alert, Martin said: "It's not like we're doing anything different because a bunch of murderers -- I call 'em terrorists -- are threatening us. Personally, I don't do anything differently than I did before. We're not changing the way we do our job because of them."
The Associated Press contributed to this report.