Galán denounced Pablo Escobar in a public rally, and supported the extradition treaty with the U.S, contrary to the wishes of the Colombian cartels that feared extradition to the U.S. After receiving several death threats, on 18 August 1989, Galán was shot and killed by hitmen hired by the drug cartels of Pablo Escobar during a campaign rally in the town of Soacha, Cundinamarca.

While a student there and only 8 years old, he joined a rally against Conservative president Laureano Gómez and intended to support the Liberal guerrillas.

When he was only a 14-year-old, Galán participated in the students protests of 1957 against the dictatorial regime of Gustavo Rojas, being arrested and spending the night in a jail despite his young age.

[3] In 1960 Galán graduated from high school with honors and began studies of law and economics in the Pontifical Xavierian University in Bogotá.

He was able to meet prominent Colombian leaders like former Liberal president Carlos Lleras (who, delighted with Galán's work, decided to write articles for Vértice Magazine) and Colombia's main circulation newspaper El Tiempo owner and also former Liberal president of Colombia Eduardo Santos during an interview in which Santos was impressed by Galán's journalist qualities.

He was also active with the Nueva Frontera weekly magazine founded by former president Carlos Lleras, which he directed in 1976 after arriving from Italy.

[2] In 1977 Galán wrote an article in one of Nueva Frontera's editorials denouncing the existence of narcotics trafficking mafias and that they were influencing the social structure of Colombia.

Under the influence of former president Lleras and after directing the Nueva Frontera Magazine for seven years, in 1976 Galán ran for councilman in the small town of Oiba in the northeastern department of Santander.

In 1980 Galán was elected as councilman for the capital, Bogotá to be named the following year as possible candidate for the presidency of Colombia amid divisions in the Liberal Party that intended to challenge the majorities of the party led by Alfonso López Michelsen and then president Julio César Turbay, but voters leaned for the conservative candidate Belisario Betancur.

Galán was growing impatient with the violence and the corruption the drug cartels led by Pablo Escobar and Gonzalo Rodríguez were imposing in Colombia, which encouraged him to try to support the weakening government by shifting the balance of power away from his dangerous enemies.

[citation needed] According to accounts the first assassination threats were calls made to Galán's home telephone number after the Liberal Party convention to nominate an official candidate.

The assassination attempt was prevented by men working for Waldemar Franklin Quintero, the commander of the Colombian National Police in Antioquia.

[12] Later on, Galán's staff received information from the Colombian intelligence services advising him of a group of hitmen staying in Bogotá that had the intention of killing him.

[12] On 18 August 1989, Galán, who was being protected by eighteen armed bodyguards,[13] was killed as he walked onto the stage to give a speech in front of 10,000 people in Soacha.

The Colombian drug cartels were worried about the possible approval in congress of an extradition treaty with the United States, and political enemies had feared Galán's increasing power would isolate many of them from the voters.

Santofimio had been previously questioned and mentioned during the investigation and his involvement was widely rumored, but apparently no direct testimonies of his role had been acquired until recently.

Velásquez, who served a 23-year sentence and died in 2020, told the Colombian press that he had initially denied Santofimio's participation due to his existing political power at the time.

In 1971 he married journalist Gloria Pachón Castro and had three children Juan Manuel, Claudio Mario and Carlos Fernando.