MIACATLAN, Mexico - A Mexican judge on Tuesday sentenced a 14-year-old US citizen to three years in prison for homicide, kidnapping and drug and weapons possession. Authorities say the teen confessed to killing four people whose beheaded bodies were found hanging from a bridge.

Edgar Jimenez Lugo, known as "El Ponchis," was given the maximum sentenced allowed for a minor in the central state of Morelos, said state prosecutor Jose Manuel Serrano Falmerol. Jimenez was tried in a state court because Mexico does not have a justice system to try minors at the federal level.

Authorities say the teenager confessed to working for the South Pacific drug cartel, led by reputed drug lord Hector Beltran Leyva.

When he was handed over to federal prosecutors, the boy calmly said in front of cameras that he participated in four killings while drugged and under threat. The bodies were found in the tourist city of Cuernavaca.

In November, stories of a hit boy, maybe as young as 12, spread after a YouTube video appeared with teens mugging for the camera next to corpses and guns. One boy on the video alleged that "El Ponchis" was his accomplice.

Jimenez was born in San Diego, California. He and a sister were arrested in December as they tried to board a plane to Tijuana, where they planned to cross the border and reunite with their mother in San Diego.

The teenager has been in a juvenile detention center in Morelos since his arrest and will serve his time there, Serrano said.

The two siblings allegedly worked for Julio "El Negro" Padilla, a reputed drug trafficker who authorities say has been fighting for control of the drug trade in Morelos.

Morelos was formerly under the control of the Beltran Leyva gang, which broke up after alleged leader Arturo Beltran Leyva was killed in a shootout with Mexican marines a year ago. The battle among remnants of the gang has caused an unprecedented spike in violence in Morelos and in neighboring Guerrero state, where the resort city of Acapulco is located.

A relative has said Jimenez was nicknamed "Ponchis" by his family because he was a pudgy child.