A few days ago, Mexican authorities captured Osvaldo Garcia Montoya, alias El Compayito, one of the most brutal of the new drug lords and the leader of the Hand with Eyes Cartel that operates in Mexico State and parts of Mexico City.
He is said to have admitted responsibility for killing more than 600 people, most of them rivals who were beheaded and further dismembered.
In fact, he was supposedly planning to kill five members of his own gang who were going to desert, and then post the gruesome murders on the internet, when he was captured.
What really drew my attention, though, was Garcia Montoya’s background: he was a former Mexican military officer who had been trained in Guatemala at the Kaibil Academy.
The Kaibils are Guatemala’s Special Operations Group, arguably one of the world’s toughest, best trained and most ruthless commando forces.
Their war cry was first coined by the Spartans: ”If I advance, follow me if I stop, urge me on if I retreat, kill me."
They  were formed in the 1970s to combat Guatemala’s leftist insurgency and quickly earned a reputation as killing machines, because of the massacres they carried out against entire villages of mainly Mayan Indian peasants.
Today they are struggling to change that image.
After the war, Guatemala’s government decided not to disband the Kaibils, but rather to use them to fight another battle: against drug traffickers and organised crime.
Kaibils have also gone to the Congo and to Haiti as United Nations peacekeepers. They are called on during hurricanes and other natural disasters to come to the rescue of ordinary citizens.
That is not, however, why they've been making the headlines recently.
I recently spent time at the Kaibils’ Academy in Guatemala’s Peten jungle. I’d gone to see just how these men were trained, and to try to understand why some of them have become a powerful weapon at the service of Mexico’s Zetas cartel.
At the entrance of the school there is a sign: WELCOME TO HELL.
All those who do the special operations course are officers, who must leave their rank insignias in an envelope until it is over. The idea is that rank no longer counts.
They must be able to survive extraordinary humiliation, abuse and psychological pressure, as well as hunger, exhaustion and danger.
“The Kaibil is trained to go [to] his limit and beyond, to survive physical and psychological demands that no normal person could," said Major Caceres, the head of the training school.
I had heard the stories about how the Kaibils were made to not only raise a pet dog and then kill it, but also to eat it raw.
I saw the signs in the canteen that read: "Food is a fuel, not a delight."
I watched as they went through their gruelling obstacle course, which requires extraordinary  energy, strength, skill and courage.
I was told that several “students” have died throwing themselves out of helicopters into rivers and other dangerous feats.
The amazing thing is that all of those who do the course are volunteers. They are fiercely proud to be a Kaibil, which despite their controversial reputation also comes with prestige.
They are undeniably good at what they do: the question is, do they do good with it?
I found that all the publicity about former Kaibils being recruited by Mexico’s violent Zeta’s cartel to train their henchmen in the finer arts of military warfare is a matter of great embarrassment to the Kaibils.
There is no denying that many of the retired Kaibils hired by the Zetas to form a sophisticated and disciplined army of their own, are likely the same ones that took part in Guatemala's wretched Dirty War.
But it is also clear that Guatemala’s government is largely to blame for not ensuring that when these soldiers retire and return to civilian life they find a better alternative to the easy money offered by organised crime.
It is absurd to think that elite soldiers, whose only profession is the art of warfare, can simply return to their poor villages to become bakers or tailors.
Most Kaibils have little choice but to work as bodyguards, or advisers for security firms, when they leave the army.
Clearly, if the state created them, it has the responsibility to ensure they can reintegrate into society without leaving them so openly at the mercy of temptation.