Colombian John Jairo Velasquez Vasquez, a.k.a. "Popeye," confessed murderer of about 250 people, is photographed at Combita prison in Boyaca in 2013. (Carlos Ortega/AFP/Getty Images)

In the heyday of Colombia's cartel wars, one of the most feared sicarios, or hitmen, went by the name of Popeye. His chin jutted out like the cartoon character's. He was Pablo Escobar's right-hand man, helping him uphold the drug-running Medellin cartel's vengeful stranglehold over Colombia in the late 1980s.

He enjoyed years of impunity during which he claims he personally killed at least 250 people, including his own girlfriend, and ordered the killings of thousands of others. He was finally caught in 1992 and convicted of just one attack, though it was a particularly heinous one and it landed him 22 years in jail. "I'd estimate I've killed around 250 people with my own hands," he once said, "but only a psychopath keeps count."

Popeye, now 54, was released from prison for "good behavior" and immediately went about reinventing himself. Now, he goes by "Popeye Arrepentido," or "Regretful Popeye." That's the name of his phenomenally popular YouTube channel, which has almost 100 videos and more than 100,000 subscribers.

In the videos, Popeye, whose real name is John Jairo Velasquez Vasquez, tells riveting stories from his years with the cartel. He has captured the imagination of a public still morbidly fascinated by Escobar and his violent apparatus. Each video on the channel starts with a slo-mo bullet crossing the screen to rock music. He told the Guardian in an interview that “it may seem like ... glorifying crime, but it’s to attract young people.”

Escobar is still venerated by some in Colombia. His birth and death anniversaries are celebrated and his grave has been converted into a shrine of sorts. His life was recently made into a hit Netflix mini-series called "Narcos." Escobar was killed in 1993 in an encounter with police.

In one video, Popeye refers to himself as "the historical memory of the Medellin cartel" and says that he is ready to "tell all." He has used the videos to confess to countless crimes, including the bombing of an airliner that killed over 100 people, but was carried out to kill just one passenger, a prospective presidential candidate. (The candidate never got on the plane and went on to become president of Colombia.)

He also uses the videos to respond to questions that often come from Colombians who are still haunted by the violence of that era. In one exchange, the brother of a murdered police officer asks Popeye if he will live up to his new name and show regret by meeting with the families of his victims. “That’s a painful question for me,” he answers. “It’s important that we could meet so I can ask for your forgiveness face to face and accept my responsibility.”

Remorse figures into many of his missives. Part of that may have been born out of his experience of therapy while in prison. For eight years, he worked with a therapist to achieve some level of rehabilitation. "Every day, I made a list of all the nasty things I said to the guards," he said. "Little by little, I changed my way of thinking and acting."

But Popeye uses the videos to comment on current Latin American affairs too. In his second most recent video, which is also his most viewed, he responds to a perceived insult made by Diosdado Cabello, a Venezuelan politician belonging to that country's ruling party. The video is titled "From One Bandit to Another," and in it Popeye calls himself a "fighter for democracy." He comes off as a breathless pop-historian as he animatedly points out the many failures of the Bolivarian Revolution. He defends himself by saying that Venezuelan politicians have killed perhaps more people than he has through their policies.

In another, he comments on Joaquín "El Chapo" Guzman, a Mexican crime lord who often draws parallels to Escobar. El Chapo was arrested earlier this year after escaping from prison a second time, and is in the process of being extradited to the United States. "His primary weakness is a lack of discipline, and his ego," says Popeye. "That's what landed him in a jail cell. He had the bad luck to be caught alive. Now he'll die in a cell."

Not Regretful Popeye.