The boy allegedly rode up on a motorcycle and opened fire on a family in the low-income Mexico City suburb of Chimalhuacan.

Another man was also arrested for the January 22 killings, and seven other members of the gang were arrested on drug charges.

The victims were holding a party at their house at the time of the attack, which also left five adults and two children wounded. It was reportedly a birthday party.

The boy’s name was not released on Thursday, but his nickname – meaning Little Chapo – is an apparent reference to imprisoned drug lord Joaquin “El Chapo” Guzman.

The motive in the killings has not been made public, but drug gangs in Mexico frequently dabble in kidnapping and contract killing.

They also kill rivals selling drugs on their territory, or people who who them money.
Mexico is no stranger to child killers.

In 2010, soldiers detained a 14-year-old boy nicknamed “El Ponchis” who claimed he was kidnapped at 11 and forced to work for the Cartel of the South Pacific, a branch of the splintered Beltran Leyva gang. He said he had participated in at least four decapitations.

After his arrest, the boy – who authorities identified only by his first name, Edgar – told reporters he was drugged and threatened into committing the crimes.

-AP