Colombian conflict dialogue, but President Barco sent an ultimatum to the guerrillas and demanded that they immediately disarm or face military retaliation. Regional guerrilla and Army skirmishes created a situation where each violation of the ceasefire rendered it null in each location, until it was rendered practically nonexistent. By 1990, at least 2,500 members of the FARC-founded Patriotic Union had been murdered, according to historian Daniel Pecáut, leading up to that year's assassination of presidential candidate Bernardo Jaramillo Ossa. The Colombian government initially blamed drug lord Pablo Escobar for the murder but journalist Steven Dudley argues that many in the UP pointed
Pablo Escobar Dolores Gaviria Berrío (d. 2006), an elementary school teacher. Raised in the nearby city of Medellín, Escobar is thought to have begun his criminal career as a teenager, allegedly stealing gravestones and sanding them down for resale to local smugglers. His brother, Roberto Escobar, denies this, instead claiming that the gravestones came from cemetery owners whose clients had stopped paying for site care, and that he had a relative who had a monuments business. Escobar's son, Sebastián Marroquín, claims his father's foray into crime began with a successful practice of selling counterfeit high school diplomas, generally counterfeiting those awarded by