Tuesday, August 25, 1987 began like any other day for Luis Felipe Vélez, president of the teachers union of Antioquia, Colombia’s most populous state. Shortly after 7 AM, Velez said goodbye to his wife and three young children and headed to the union’s office in downtown Medellín.

But as the thirty-three-year-old was about to enter the modest adobe-brick building, two assassins leapt out of a green Mazda 626 and opened fire, riddling his body with bullets. Velez died two hours later.

Word spread quickly among human rights activists, teachers, and Vélez’s colleagues in the Association of School Teachers of Antioquia, and by 5 PM a large crowd had gathered at the union office for a vigil.