Mexican officials say Jimenez led a group of young killers, ages 12 to 23, and was paid $3,000 per hit. The teen said he started working for the cartels when he was 11.
In a confession made before reporters, the teen, nicknamed "El Ponchis," admitted to chopping off the heads of his victims, saying "I participated in four executions. Cartel leaders made me smoke marijuana before the kills. I had to cut the throats because they would kill me if I didn't do it."
Jimenez was arrested as he attempted to board a plane bound for Tijuana. Authorities say the boy and two of his sisters were planning to cross the border into San Diego to hide out with his stepmother.