Pardo Leal studied law in Universidad Nacional de Colombia, where he graduated as a lawyer in 1963.

Following the peace conversations between the FARC and the government of Belisario Betancur, the Unión Patriótica political party was formed, and Pardo was called as an advisor.

As party president, Pardo became vocal in denouncing this selective killings and accusing the government of overlooking those crimes, or even committing them.

On the day of his death he had decided to dispatch his security and kept only one of his bodyguards as he went to his farm in the La Mesa town, near to Bogota.

[6] Drug lord José Gonzalo Rodríguez Gacha, also known as "the Mexican", was apparently involved in the murder as a sponsor.

An April 1988 report by Amnesty International charged that members of the Colombian military and government would be involved in what was called a "deliberate policy of political murder" of UP militants and others.

By 2003–2004, the official legal representatives of a partial number of UP victims presented a concrete death toll of about 1,163 to the Inter-American Commission on Human Rights (IACHR), of which 450 (38%) were attributed directly to paramilitary groups.