Pablo Escobar’s most notorious hitman, known by the nickname Popeye, died on Thursday at age 57 after a life of crime he celebrated on YouTube, Colombia’s prison authorities said. Jhon Jairo Velasquez had boasted of killing hundreds of people for his “boss” Escobar, the infamous drug lord killed by Colombian police in 1993 while on the run to avoid extradition to the United States. Velasquez died at the National Cancer Institute in Bogota, where he’d been receiving treatment for stomach cancer since December 31. He spent 23 years in prison after giving himself up to law enforcement authorities in 1992 but was arrested again in May 2018 on accusations of “conspiracy to commit crime and extortion,” prison authorities said. Velasquez had been a close associate of Escobar as he ran a drug empire from Medellin that exported thousands of tons of cocaine to the US, making him one of the richest men alive during the 1980s and 90s. Escobar responded to efforts to extradite him with car bombings, kidnappings and assassinations targeting political leaders, journalists and judges.