Diario (see story here) has reviewed documents released by the Mexican Defense Department (Sedena) and they appear to point to the Sinaloa cartel as the responsible party in much of the violence that has afflicted the Valle de Juarez in the past few weeks and months.
For those who don't follow Juarez closely, it might be useful to begin with the conventional wisdom (CW) that much of the violence in Cd. Juarez in the past two years has been caused by conflict between the Juarez cartel (also known as "La Linea" or the Carrillo Fuentes cartel) and the Sinaloa cartel, headed by "Chapo" Guzman. According to this CW the Sinaloa cartel has been fighting to create its own organization in Juarez, which used to be controlled exclusively by the Juarez cartel, created in the late 1980s. I use the term "conventional wisdom" because it is difficult to know exactly what is happening at any given time in the underground waters of drug trafficking organizations. Is isn't the kind of thing one asks about in Cd. Juarez. It is not infrequent that mis-information or dis-information or rumor or conjecture comes to be known as fact, and agencies that may have good information rarely share this with the public.
At any rate, according to Sedena documents, Gabino Salas Valenciano, a.k.a "El Ingeniero" ("The Engineer") acts on behalf of the Sinaloa cartel in the Valle de Juarez. He was arrested in February 2008 by the Mexican Army, in possession of drugs, guns, and ammunition. He was subsequently sentenced to nine years of jail, but was released by the Third Federal Judicial Tribunal in October of 2008, according to Diario, for "inconsistencies in the circumstances" related to his arrest in the army's account. From the time of his release newspaper stories began to associate Salas with violent activity in the Valle de Juarez, such as the burning of various properties in the village of Barreales in October of 2008.
At the time of his arrest Salas was believed to be the head of a cell of assassins working for the Juarez cartel. In November 2009, however, a year after he was released from jail, Sedena identified him as head of a cell of assassins working for the Sinaloa cartel. The Diario story suggests his switch may have been motivated by a desire to avenge his brother's death. His brother, Valente Salas Valenciano, was found murdered in May 2008 on a main thoroughfare in Cd. Juarez (Ave. Vicente Guerrero) with a sign attached to him , apparently written by assassins for La Linea, suggesting Valente was killed because he worked for the Sinaloa cartel.
The Diario story also suggests the Sinaloa cartel has been engaged in an effort to take full control over the Valle de Juarez ever since the arrest of Rodolfo Escajeda, a.k.a. "Rikin," in September 2009 by the Mexican army in Casas Grandes. Diario cites DEA sources to the effect that Escajeda was known to control drug trafficking in the Valle de Juarez from 2000-2006. Sedena documents report that shortly after Escajeda's arrest a sign was found hanging in the Valle saying, "Now that your daddy Rikin is gone, you 'hijos de puta,' you'd bettter get lost. This is your last chance or we'll come in and bust you up....Sincerely, Sinaloa Cartel."