Mexico City (CNN) -- A 14-year-old accused of ruthless killings on behalf of a Mexican drug cartel boss faced a battery of questions from reporters after authorities detained him. And he answered, point-blank, as camera flash bulbs flickered.

"I slit their throats," he said, describing what he said was the killing of four people.

The teen told reporters after his capture Thursday night that he was an orphan who joined the Pacifico Sur drug cartel when he was 12. He said Julio "El Negro" Padilla, one of the group's alleged leaders, threatened him.

"I either work or he'll kill me," the 14-year-old said.

Analysts say the case offers a glimpse into Mexican drug gangs, which are increasingly recruiting youth to help with their turf battles.

Blog: Accused teen hit man in Mexico admits to slayings

"This won't be the last time we hear stories of young children picking up arms and killing people because it pays, and because they think it's cool," said Sylvia Longmire, a former U.S. Air Force officer and senior intelligence analyst specializing in Latin America and Mexico's drug war.

With his hands shoved into the pockets of his cargo pants, the 14-year-old told reporters that he was paid weekly in dollars and pesos. But in answering questions about whether he knew what he was doing when he allegedly participated in the killings, the teen said he was under the influence of drugs and unaware of his actions.

"No, I didn't know," he said.

Troops standing beside the teen while the youth was interviewed wore masks to hide their faces -- a common sight in Mexico, where clashes between authorities and cartels have intensified since President Felipe Calderon announced a crackdown shortly after he took office in 2006.

But the teen's face was clearly visible.

Martin Perez, director of Mexico's Children's Rights Network, said late Friday that authorities should not have given television cameras and newspaper photographers access to the 14-year-old.

"It was completely inappropriate, the form of presenting him in front of the media," he said.

"Everyone has the right to be presumed innocent," he said. "Also, it could put his life at serious risk. We have to remember that this is a fight between criminal organizations."

Morelos state Gov. Marco Adame told reporters Friday that he has asked for an inquiry into the teen's migratory status after preliminary reports indicated that the 14-year-old was carrying a birth certificate issued in San Diego, California, when authorities detained him and two of his sisters at an airport in central Mexico.

A U.S. State Department spokesperson said Saturday that the boy's identity and citizenship were still being investigated.

A spokeswoman for the Mexican attorney general's office said authorities detained the 14-year-old Thursday evening on suspicion of working as a drug-cartel hit man, but declined to provide details.

An anonymous phone tip alerted authorities that the teen was at the airport and heading to Tijuana, Mexico, the state-run Notimex news agency reported.

The 14-year-old said he went to school before joining the drug gang.

"I studied," he said, adding that he later dropped out. "I didn't want to study anymore ... I didn't like it."

CNN's Claudia Dominguez, Rey Rodriguez, Nick Valencia and Krupskaia Alis contributed to this report.