Mexican Drug Cartels Recruiting Texas Children? American Teens Open Up About Forced Life As Hit Men [VIDEO]

At 15 years old, Gabriel Cardona recalls being recruited by the fiersome Mexican drug cartel the Zetas to start a secret operation that involved training American youths in Laredo, Tx. to kill. Now 26, Cardona has lost track of how many people he murdered since he began as a teen assassin. He and 24-year-old Rosalio Reta are currently sitting in a Texas prison serving life sentences for their crimes.

"It's a violent world, man, when you're in Mexico," Cardona said to reporters with CNN when probed about the total body count he accrued as a young servant of the cartels.

What both men do remember is serving under Miguel Angel Trevino, a longtime leader of the Zetas who was recently arrested in Mexico. The two recalled his ruthless tactics and tyrannical leadership. He expected an orderly following and for his underlings to be able to execute anything he was willing to do -- and that was just about anything.

"I've known this man and he's not going to tell you to do something he won't do himself," Reta said. "And that's why a lot of people follow him."

The two were arrested as young boys seven years ago. Reta's first kill was at 13. By 19, he was in solitary confinement at a Texas prison serving a 70-year sentence for murder, the Daily Mail reported. Cardona is serving 80 years. Reta has spoken out several times since his arrest. He has slowly transformed from the stoic, cold-blooded, teen killer to a young man begging for forgiveness and understanding.

Reta was a good student at a young age. He grew up playing sports and had a penchant for mischief. The temptation of the night life in Nuevo Laredo, located just across the river, fascinated him. One night, Reta travelled into Nuevo Laredo with some friends and found a group of people beating and torturing a man into giving the band of thugs information. An argument broke out due to Reta's presence because he was a stranger to the group. A man handed him a gun and gave him an ultimatum: Kill or be killed.

"They were torturing people and getting information from them. I couldn't believe what I was seeing. People getting tortured, killed, decapitated. It was kind of hard to believe," Reta said. "I shot him. I had to."

Reta was trained at a secret camp that he describes as something out of a U.S. military training facility after his life as a hitman unexpected began. He killed an estimated 30 people. Cardona killed somewhere around 20 or 30. Cardona is believed to have been involved in the murder of two American teens that he allegedly slashed with a bottle, siphoned their blood and toasted to La Santa Muerte, or "the Holy Death," which has become a common symbol for Mexican cartels.

It is said that Nuevo Laredo is a major hub for child recruits. Young teens looking for a bit of fun and trouble often find themselves at a nightclub in the city called Eclipse. That's where drug cartel members and leaders linger in search of new recruits. The promise of money, good times and life on the edge is what seals the fate of many youths.

"The cartels - they just seduce you. They wave that power, that cash, the cars, the easy money. And these kids all have that romantic notion they are going to live forever," Detective Roberto Garcia of the Laredo Police Department said.

The two were paid $500 a week, and between $10,000 and $50,000 in cocaine for each killing they successfully executed. They lived in a large house for their services and purchased luxury merchandise. Reta dropped out of school in sixth grade. Cardona left in ninth. Cardona was arrested in 2009 for killing seven men and conspiracy to kidnap and kill in a foreign country. Reta's story took a different turn when he accidentally killed civillians in an assassination attempt. He turned himself in to police and now faces life in solitary confinement. Upon his arrest, however, he bragged about his aim and promised to look police in the eyes as they shot him if he was unable to take someone out from a distance. Now, he says he regrets the way his life played out.

"I've come to regret everything I've done. I couldn't take it anymore. It was real hard for me. I wasn't living my life," he said.