In the wake of that event, Guatemala's human rights ombudsman, Ramiro de León Carpio, succeeded as president, according to the constitution. He appointed Pérez as his presidential chief of staff, a position he held until 1995. Considered a leader of the Guatemalan Army faction that favored a negotiated resolution of the 30-year-long Guatemalan Civil War, Pérez represented the military in the negotiations with guerrilla forces. They achieved the 1996 Peace Accords.