Velasco was the sicario lieutenant of the Medellín cartel, succeeding Roberto Ramos after the latter's death in 1991.
Velasco was one of Escobar's most loyal and trusted sicarios. Velasco held a disliking towards Pablo's other lieutenants, Gerardo Moncada and Fernando Galeano; and convinced Pablo that they were stealing from him, leading Pablo to murder them inside the La Catedral prison. He survived the La Catedral siege, and became a high ranking member.
Velasco's Corpse
He was captured by the Los Pepes in October of 1992, and was tortured by Don Berna, Escobar's former head-of-security. Velasco failed to resist torture, and gave away the name of three of Escobar's accountants, and the fact that Lion was returning from Miami to meet Escobar. He was later killed, and his body was hung in the public.