John Jairo Velasquez, nicknamed Popeye, admitted to being involved in as many as 3,000 murders and killing 300 people in the 1980s and 1990s. He also gave information that led to the conviction of ex-Justice Minister Alberto Santofimio, who ordered the hit on his political opponent Luis Carlos Galan before the 1990 presidential election.
Galan's tough stance against the drug cartels was a platform he used in the election. However, he was gunned down before he could win. Santofimio, who is currently serving a 24-year sentence, was closely linked to Escobar.
Velasquez was escorted by police as he left the high-security prison. He will be on probation for the next four years.
2014: The Year in Music [PHOTOS]