Sicario is the harrowing story of a 12 year-old named Jairo who takes a job as a hit man in order to support his desperately poor family. Jairo proves to be frighteningly adept as a local druglord's hired killer, using his quickness and innocuous appearance to his advantage. However, after Jairo gets over the initial joy of seeing his substantial earnings, he soon loses his stomach for the job and wants to quit. Unfortunately, Jairo quickly finds that it is impossible to quit when you work for an organized crime syndicate.
La violencia en el barrio es constante. En las noches de ocio, los muchachos se drogan y asaltan transeúntes. Jairo, Hastiado de su condición marginal, de su pobreza e infierno familiar, entra en el mundo del crimen al participar en un asalto. Pronto Jairo estará inmerso en el mundo de matar por dinero y morir si es necesario: El Sicariato.