"They call me the Wolf," said the 25-year-old human smuggler sitting in front of me, sipping a Coke and stepping away for frequent cellphone calls.

"Everybody says we're the problem, but it's the reverse. The gringos don't want to get their hands dirty. So I bring them the Mexicans and Central Americans to do the dirty work for them," he says, smiling.

U.S. authorities claim that human smugglers like El Lobo (the wolf) are at the heart of the current border crisis because they have facilitated the travels of the 57,000 unaccompanied immigrant children who've been apprehended in South Texas since October.

"We cross them in inner tubes. If they're 3 or 4 years old, I have to cross them myself. I can't let them drown," he says.

The Wolf wears Reeboks with pink soles, a black polo shirt and a thin mustache. He's handsome in a bad-boy sort of way. We sit in an open-air lunchroom on a back street in Matamoros, across the river from Brownsville, Texas. He's explaining his rates: $2,500 from Chetumal, Mexico, all the way to Matamoros — 1,200 miles. The actual river crossing is another $500 to $1,000, "depending on the size of the kid."

The Wolf says he used to smuggle adults, but now he specializes in children because it's easier and just as profitable. First, his organization can take a group of Central American children in a bus through Mexico and more easily evade Mexican authorities, who are looking for adult immigrants to deport.

Second, once he crosses the Rio Grande he doesn't have to continue with the group to San Antonio or Houston — the most perilous part of the journey. "Children just give themselves up [to the Border Patrol]," he explains. "Adults have to flee."

In low tones, he confides that he is not part of the Gulf Cartel or Los Zetas, which control all river access on the Mexican side of the lower Rio Grande Valley. Like all freelance smugglers, to use the river he has to pay the cartel un derecho de piso, a user's fee, of 10 percent of the contract.

Federal border authorities demonize coyotes as ruthless criminals who kidnap, rape and abandon their clients. But it's more complicated than that. There are, to be sure, bad coyotes who do abuse their clients. But, as in any business, not everyone is the same.

Five years ago, I interviewed a petite, 29-year-old female coyote who worked out of Piedras Negras, Mexico, who was in high demand for her considerate treatment of her clients. This came to me from a local priest, who counted her among his congregation.

"Being known in the communities and having a good reputation matters," says David Spener, a sociologist at Trinity University in San Antonio, who has studied human smuggling networks along the U.S.-Mexico border. "I mean, would any parent in their right mind want to leave their child in the hands of Los Zetas?"

I ask El Lobo about the terrible reputation coyotes have in the media.

"We specialize in smuggling young kids — 13 and below," he explains. "The youngest we've smuggled was 2 years old. We have to make sure nothing happens to them, that they eat, that they're protected and they arrive well."

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