As reported by Milenio, the number of "executions," or killings linked to organized crime, tallied 982 in December, the first month of Peña Nieto's presidency. This represents a three percent bump from November, in which Milenio registered 949 such murders, and an 11 percent increase from October, when the figure stood at 888. The number, however, remains a significant drop from September’s 1,145, and is well beneath the worst months of the Calderon presidency.

The statistics amply demonstrate the persistency of Mexico’s security problems, despite the presidential changeover. The nearly 1,000 murders also encompass many of the more malign aspects of Mexican violence over the past several years. There were 50 murders of police and government officials, for instance. There were also a handful of acts of mass bloodshed, such as a jailhouse riot that killed 24 in Gomez Palacio, Durango, and a wave of indiscriminate attacks on houses and businesses in Guadalupe y Calvo, Chihuahua, which ended the lives of 11 people. Whatever expectation of a sudden peace stemming from Calderon’s exit has been erased from the map.

There are, nonetheless, some significant shifts in the violence registered by Milenio. For the first time in three months, Chihuahua reclaimed the top spot in the number of executions, with 122. Guerrero, previously the most violent state, saw a sudden transformation: with just 40 murders, it was the 15th most violent state in the country, out of a total of 32. This marks the lowest number of executions registered by Milenio in Guerrero since January 2012.

Two other states frequently among the bloodiest were similarly calm: Tamaulipas and Nuevo Leon. Both of these regularly figure among the deadliest states in Mexico. While Tamaulipas' reputation as a den of organized crime is longstanding, Nuevo Leon, in contrast, used to be known as one of the safest regions of northern Mexico. However, following the split between the Gulf Cartel and the Zetas in 2010, security rapidly declined as the two erstwhile allies fought over their old turf. Largely because of this deterioration over the past three years, Nuevo Leon became one of the five states with the most executions under Calderon.

Guerrero's pacification has turned Coahuila into the second most dangerous state in the country, according to Milenio's tally of murders. This marks a further descent in a region that has been steadily deteriorating since 2008. Mexico's third most dangerous state is Sinaloa, perennially among the most violent districts in Mexico. But Mexico's top five most violent states was rounded out by a surprising pair: San Luis Potosi and Zacatecas, both of which witnessed 53 executions.

The violence in San Luis Potosi, Zacatecas, and Coahuila is especially interesting when contrasted to the newfound tranquility in Tamaulipas and Nuevo Leon, because all of them are part of the Zetas' turf. Tensions among different wings of the group have been reported since last spring, and the death of Zetas boss Heriberto Lazcano, alias "Z-3," in October promised to provide another jolt to the violence, threatening to fracture the group into several different pieces. 

But that hasn't happened, at least not across the board. It is not the traditional home of the Zetas (Tamaulipas, Nuevo Leon, and Veracruz) that has been overrun with the violence, but the more peripheral states, in which their ties are not as deep. It's not clear if the surge in killings in San Luis Potosi, Zacatecas, and Coahuila is primarily due to further infighting or because other gangs are moving in, trying to take advantage of a weakened group by eating away at the edge of their empire.

Whatever the case, the fall in killings in Nuevo Leon suggests that Lazcano’s partner and rival Miguel Angel Treviño, alias "Z-40," has managed to consolidate his hold over the group. This is even though some factions within the Zetas appeared to turn against him last year. For now, it seems as though things are calming down within the heart of the Zetas' territory. 

It is not clear if this will remain the case. If not, and if Treviño loses his grip over the criminal organization, it is likely that Mexico’s northeastern states will once again populate any list of Mexico’s most dangerous regions.