He received a doctorate in economics at the Faculty of Law and Social Sciences at the National Autonomous University of Mexico and stayed in teaching.
In 1982, during an argument he killed two people and wounded another one, ran and hid from the Mexican justice system. In 1989 he returned to Guatemala, joined the Socialist Party. In 1993 he became the general secretary of the party, and in 1994 he was elected to parliament and headed the parliamentary group of the party. Alfonso headed the parliamentary committee on municipal issues, economy, foreign trade and parliamentary associations. In 1995 the case against the murder was closed by the expiration of the limitation period. In the same year, due to intra-party aggravated conflicts he left the party and joined the far-right Republican Front of Guatemala, which was headed by General Rios Montt, responsible for the mass murder in the 1982-1983 dictatorship. In December 1999, he won the election, and January 14, 2000 was inaugurated as the President of Guatemala. At the moment, he has to flee in Mexico.