The US Treasury Department's Office of Foreign Assets Control (OFAC) on Sept. 21 imposed Kingpin Act sanctions on four Colombian nationals and 12 companies said to be linked to Joaquín Guzmán Loera AKA "El Chapo"—head of Mexico's Sinaloa Cartel. Guzmán faces charges in the US, but remains at large. (WSJ Corruption Currents blog, Sept. 20) The move comes amid increasing charges that US law enforcement—as well as the Mexican government—is favoring the Sinaloa Cartel in Mexico's bloody narco wars.

Leaders of the Mexican Electrical Workers Union (SME) reached an agreement with Mexico's federal government on Sept. 13 that ended a sit-in the unionists had been holding in Mexico City's main plaza, the Zócalo, since March. In exchange for stopping the protest, the union received a pledge that the authorities would negotiate a way for some 16,720 laid-off members to return to work. The government also agreed to free up union funds worth 21 million pesos (about $1.6 million) that it had frozen and to review the cases of SME members arrested in the two years of struggle between the authorities and the unionists.

Two half-naked mutilated bodies left hanging from a bridge in the Mexican border town of Nuevo Laredo, Tamaulipas, were accompanied by "narco-messages" scrawled on cardboard saying the killings were an example of what will happen to "Internet snitches" (relajes del internet). The message was signed "Z," an apparent reference to Los Zetas. The threat was evidently directed against Blog del Narco, which runs graphic accounts and video clips of cartel war casualties, and Frontera al Rojo Vivo, a forum set up by Monterrey newspaper El Norte. Websites have taken up the slack as Mexico's "official" media have stopped aggressive coverage of the cartel wars in response to relentless threats and attacks against journalists. (NPR's The Two-Way blog, Houston Chronicle, Sept. 15; AFP, SDPnoticias, Sept. 14)

Leaders of 71 unions in 18 countries have signed a letter to Mexican president Felipe Calderón Hinojosa expressing "grave concern for the lack of progress in the investigation" of the April 2007 murder of an organizer for the Ohio-based Farm Labor Organizing Committee (FLOC) in Monterrey, in the northern state of Nuevo León. After holding a press conference in Mexico City on Sept. 8, FLOC president Baldemar Velasquez delivered the letter to the Mexican president's official residence, Los Pinos.

Mexican marines shot and killed Gustavo Acosta Luján in the early morning of Sept. 1 in his home in Jardines de San Andrés, Apodaca municipality, in the northern state of Nuevo León. According to the Secretariat of the Navy, the marines, responding to an anonymous tip, were fired on from inside the house, and Gustavo Acosta, an "alleged criminal" with the alias "M-3," died in the operation. The marines said they found a 9 mm submachine gun, an AR-15 rifle and quantities of cocaine in the house. Mexican president Felipe Calderón Hinojosa has been using soldiers for police work in northern Mexico since militarizing the "war on drugs" shortly after he took office in December 2006.

The US Justice Department announced on Aug. 30 that Kenneth Melson, the acting head of the Bureau of Alcohol, Tobacco and Firearms (ATF), had been reassigned to another position in the department and that Dennis Burke, the US attorney for Arizona, was resigning from his post. The department didn't explain the reason for the changes, but they were clearly fallout from Operation Fast and Furious, a bungled ATF program that allowed some 2,000 weapons to go from the US to Mexico, where they were probably used in drug cartel violence.

A team of armed men who arrived in sport utility vehicles and a pickup truck entered the crowded Casino Royale in the northern Mexican city of Monterrey on Aug. 26, ordered the staff and patrons out—and set the building ablaze with a flammable liquid while people were still scrambling for the doors. At least 52 were killed. President Felipe Calderón said: "It is evident we are not facing common delinquents, we are facing true terrorists who have surpassed not only the limits of the law but...respect for life."

US agents have been posted in recent weeks at a Mexican military base to carry out intelligence and planning work with Mexican officials against drug cartels, according to an Aug. 7 article by New York Times reporter Ginger Thompson. The team includes "fewer than two dozen” agents of the Drug Enforcement Administration (DEA), Central Intelligence Agency (CIA) officials and "retired military personnel members from the Pentagon's Northern Command," Thompson wrote. They are working at a "compound modeled after "fusion intelligence centers' that the United States operates in Iraq and Afghanistan to monitor insurgent groups." The US is also "considering plans to deploy private security contractors” in a counter-narcotics unit of the Mexican police, according to the article.