As proved by the Peten killings, the Zetas' presence in Guatemala has drawn attention because of their willingness to use brutality. In contrast to the other Mexican cartel with sizeable presence in Central America, that of Sinaloa, the Zetas have frequently used extreme violence to establish control over a territory. While the Sinaloans have attempted to maintain their operations in Guatemala's western Huehuetenango department by buying the silence of authorities and negotiating deals with local traffickers, the Zetas have proven themselves more disposed to fight and kill their rivals.
In other Northern Triangle countries, the Zetas have been more accomodating to local gangs, although no less ambitious in expanding their operations. As recently noted by El Salvador President Mauricio Funes, the Zetas have made contact with gangs like the Mara Salvatrucha (MS-13) and the Barrio 18 (18), which echoes statements made by the president and the defense minister in 2010.
In El Salvador, the Zetas use gangs as drug peddlers and hired assasins, not for the purpose of trafficking cocaine via international routes. However, there is evidence that MS-13 is interested in deepening their relationship with the Zetas, with some cells reportedly soliciting training in combat from the Mexicans.