Facing serious political and economic problems at home, on Jan. 6 Mexican president Enrique Peña Nieto made his first official visit to Washington, DC, since taking office in December 2012. A private meeting at the White House with US president Barack Obama lasted longer than was scheduled, and the two presidents didn't take questions when they spoke with the press afterwards. The US has been following the "tragic events" involving seven deaths and the abduction of 43 students the night of Sept. 26-27 in the southwestern Mexican state of Guerrero, Obama told reporters, and the US would continue to aid in investigations and in the fight against drug cartels. Obama also praised Mexico's efforts to keep Central American migrants from reaching the US border, especially during the child migrant "crisis" in the summer of 2014. Peña Nieto promised that Mexico would help the US and Cuba normalize relations. (La Jornada, Mexico, Jan. 7)

Reuters on Dec. 10 reported that the alleged Chicago jefe of Mexico's Guerreros Unidos narco-gang faces federal charges with seven others for a plot that involved moving heroin and cocaine to the Windy City in passenger buses. Pablo Vega Cuevas and his brother-in-law, Alexander Figueroa, both of Aurora, Ill., were arrested in Oklahoma; three suspected accomplices were busted in the Chicago area. Warrants have been issued for three others, including one believed to be in Mexico. The investigation led to the seizure of 68 kilos of heroin, nine kilos of cocaine and more than $500,000 in cash. "These arrests will have a significant impact on the supply and distribution of heroin and cocaine throughout the Midwest," Dennis Wichern, the DEA's Chicago special agent-in-charge, said in a statement.

On Dec. 12 a federal judge in Mexico City acquitted Raúl Salinas de Gortari, brother of former president Carlos Salinas de Gortari (1988-1994), of corruption charges in a case that has been argued in the courts since 1996. The Federal Attorney General's Office (PGR) charged Raúl Salinas with unlawful enrichment involving some 224 million pesos—about US$14.7 million at the time—that had gone missing from a secret presidential discretionary fund between 1990 and 1994. Salinas was cleared by a federal court on July 31, 2013, but the PGR appealed that decision. The Dec. 12 ruling, which is final, concludes that the PGR failed to prove the charges, bringing the high-profile case to a conclusion after nearly 19 years. Once he had delivered his verdict, the judge left for a vacation.

Police agents in San Fernando in the northeastern Mexican state of Tamaulipas aided Los Zetas drug gang in carrying out massacres of hundreds of Central American migrants and others in 2010 and 2011, according to a partially redacted document declassified by Mexico's Attorney General's Office (PGR). Although collusion between local Tamaulipas police and criminal gangs was already well known—US diplomatic cables released by the US government in 2013 discussed it, and locals refer to the police as "polizetas"—this is first time that the PGR has been required to release a document from an ongoing criminal investigation. Previously federal prosecutors had insisted that Mexican freedom of information laws didn't apply to open investigations. The document is now available on the website of the Washington DC-based National Security Archive, along with other relevant documents, including reports from US government agencies and US diplomatic cables released by the WikiLeaks group.

The sentencing last month in a case related to the Sinaloa Cartel's Chicago connection provided further fodder for the increasingly plausible conspiracy theory that the DEA protected Mexico's biggest criminal machine. Federal Judge Ruben Castillo sentenced Alfredo Vázquez Hernández, who had been extradited after serving a sentence in Mexico, to 22 years in prison for shipping 276 kilograms of cocaine to Chicago hidden in railway cars. Federal prosecutors said Vazquez was a top-ranking operative of the Sinaloa synidcate, who arranged airplanes, submarines, trains and trucks to move cocaine from Colombia to Chicago via Mexico. Vazquez was characterized as a lifelong friend of the cartel's now-imprisoned top kingpin "Shorty" Guzmán. Judge Castillo said this hadn't been proved, but stated: "Given the amount, it's nonsensical to think this was this defendant’s inaugural voyage into cocaine trafficking."

On Dec. 13 the left-leaning Mexican news magazine Proceso published an investigative report challenging the government's account of the abduction of 43 students and the killing of three students and three bystanders the night of Sept. 26-27 in Iguala de la Independencia in the southwestern state of Guerrero. Based on cell phone videos, interviews, testimony by witnesses and leaked official documents, the report's authors, Anabel Hernández and Steve Fisher, claim that agents of the Federal Police (PF) were involved in the attack on the students, that the Mexican army was at least complicit, and that the administration of President Enrique Peña Nieto has been covering up the role of federal forces.

The remains of one of 43 students abducted the night of Sept. 26-27 in the southwestern Mexican state of Guerrero have been identified by DNA tests, parents of the missing students said on Dec. 6. Technicians in Innsbruck, Austria, established that one of 14 bone fragments sent them by the Mexican government came from the body of Alexander Mora Venancio, a 19-year-old student at the Raúl Isidro Burgos Rural Teachers' College in the Guerrero town of Ayotzinapa; gang members and municipal police had detained him along with 42 other Ayotzinapa students in Iguala de la Independencia during attacks which also left three students and three bystanders dead. The bone fragments were found in a dump near Iguala in Cocula municipality after three members of the Guerrero Unidos ("United Warriors") gang told federal authorities they had helped burn and dispose of the bodies there.

Hundreds of Mexican immigrants and other activists held actions in at least 47 US towns and cities on Dec. 3 to protest the abduction of 43 teachers' college students by police and gang members in Mexico's Guerrero state in September; each of the 43 students had one of the actions dedicated to him. The protests were organized by UStired2, a group taking its name from #YaMeCansé ("I'm tired now," or "I've had it"), a Mexican hashtag used in response to the violence against the students, who attended the Raúl Isidro Burgos Rural Teachers' College in the Guerrero town of Ayotzinapa. The protesters focused on US government financing for the Mexican government—especially funding for the "war on drugs" through the 2008 Mérida Initiative—but they also expressed outrage over the US court system's failure to indict US police agents in two recent police killings of unarmed African Americans.