TIJUANA – Fourteen-year-old Luis Alberto is blond, thin and has a penetrating gaze. He could well be a rapper given his shaved head and the continuous movement of his hands while he talks. Or he could be an ordinary youngster who spends hours playing videogames or listening to music on his MP3.

For three weeks he's lived at the Recovery Center for Addicts, a shelter on the city's east side that houses 500 addicts, 20 per cent of them under age 17.

Luis Alberto, whose name is being withheld because he is a minor, admits that he is addicted to methamphetamines, which he said peddled in east-side neighborhoods for two years.

"They brought me here because I sold meth," he explained.

He said that he made between $11 and $15 per packet, and that he and his friends sold some 40 packets a day. The teen said that his boss made about $85 a day and he and his friends could sell any leftover drug. In a few minutes they could make $22 to $30 effortlessly.

The sums may seem small by U.S. standards, but in impoverished neighborhoods with few options to make money, the represented significant income.

"I spent it buying a little food and more drug," he said,

He is just one more link in a long chain that joins the drug trade to adolescents, who are increasingly being used by the cartels as "mules" to move drugs from one place to the other and as street sellers.

"Minors are cheap, disposable labor for organized crime in an environment where there are few jobs and recreational opportunities for them," said Victor Clark. "The business of selling and using drugs has increased very fast."

The social anthropologist, a specialist on drug trafficking on the border, said it's a recent phenomenon that more young people are being used as "mules" to move drugs into the United States or from one side of the city to another.

Traditionally, the cartels used adolescents as lookouts, a type of street spy that warned them when the military or police entered an area; until now they had not become central pieces in street level drug dealing, Clark said.

Ramón Arreola, the academic director of the rehabilitation center called Cirad, which treats a total of 500 adult and minors who are addicts, said illegal drugs continue to be available on the streets, despite the government's years-long crackdown on traffickers.

What's new, he said, is the use of adolescents to sell drugs. That was not the case two years ago. His center is treating four or five such young dealers a month, in addition to the 25 or 30 who are treated there for drug addiction.

Authorities have also taken notice of this trend. Though they do not have figures on the number of teens arrested who were carrying drugs – the law prohibits keeping the criminal records of adolescents – police believe that this practice has gone up in the last two years.

In one of the latest cases, state police officers reported the arrest of José Javier N., 17, who they had detained in the city's red light district of zona Norte carrying 241 packages of marijuana wrapped in aluminum.

According to the Baja California Public Safety Department, there are 270 adolescents housed in the prison for minors in Tijuana, called Consejo Tutelar, for working as "mules" for criminal cells, which is unusual for that detention center.

The state Attorney General's Office has gathered a great deal of evidence that the mafias are recruiting teen-agers and young people to steal cars and transport drugs.

Attorney General Rommel Moreno has said at various public events that drug cartels are taking advantage of minors under age 18, who enjoy wide legal protection in Mexico.

By law in Baja California, adolescents ages 12 to 17 can receive a maximum sentence of seven years, even when they have committed major crimes, including murder.

Moreno said that organized criminals exploit the difficult social and economic situations teen-agers face daily, turning many of them into drug dealers.

Almost parallel to the emergence of the teens being used as "mules," rehabilitation centers have reported an increase in adolescents who are addicted to drugs, particularly methamphetamine, the cheapest drug on the black market.

Meth has become the drug of choice for many young people and the working class precisely because of its low cost on the street and because it produces a longer sense of euphoria than heroin or cocaine, said Mario Anguiano, who rehabilitated from drugs 14 years ago and now counsels addicts and is a family therapist.

Meth, which comes in the form of a pill, in fact has displaced other illegal drugs in the city, agreed José Héctor Acosta, the director of 37-year-old organization that offers medical treatment for drug addiction in Tijuana, called the Unidad de Tratamiento del Centro de Integración Juvenil.

According the National Survey of Addictions, Tijuana has had the greatest number of meth users since 2002. The survey also shows that Tijuana has the second most number of cocaine addicts in the country, and the third most of marijuana since 2008. The so-called gateway drug on the border is not alcohol but meth or marijuana, which is different from any other region in Mexico.

A mental health survey conducted in the state's public schools from 2008 to 2011 showed that 106,000 students are at risk of abusing drugs given the conditions of their lives: disintegrating families, parents who are addicts or neighborhoods where the sale and abuse of drugs are common.

Luis Alberto, the adolescent at the treatment center, said he was not there by choice. Authorities had sent him there. But he acknowledged that he had started to feel better about himself.

"I do want to get out but at the same time I don't. I know I'm going back to the same. What I miss the most about being here is soccer. To be honest, I like soccer more than the drug. Sometimes, my friends would say that we should go get high. I would say no, I just wanted to keep playing."

omar.millan@sandiegored.com