He is the brother of the late former general Efraín Ríos Montt, a dictator accused of genocide in Guatemala during the period when he was in power from March 1982 to August 1983.

He still supported anti-government political speeches of the Guatemalan Catholic Church - protests against repression, calls for active social policies and the fight against poverty.

On 26 April 1998 Bishop Juan Gerardi was assassinated, two days after publishing his report Guatemala: Never Again, where he presented evidence forty years of repression in that country: 200,000 Indians killed and one million exiled.

Mario Enrique Ríos Montt took over in this year his duties in the Office of Human Rights of the Archdiocese of Guatemala (ODHA)[3] and became an influential and powerful opponent of his brother.

[5] On October 2, 2010, Pope Benedict XVI accepted his resignation for reasons of age[6] and on July 26, 2011, Montt was appointed apostolic administrator of the Vicariate of Izabal,[7] where he replaced Bishop Gabriel Peñate Rodríguez till 9 February 2013.