Early in his career, he became involved in representing political prisoners. As a result, he was arrested by the Argentine military dictatorship and subjected to torture and administrative detention for 18 months. During this period, Amnesty International adopted him as a "Prisoner of Conscience," and in 1977, he was expelled from the country and moved to the United States.[4]
Subsequently, Mendez worked for the Catholic Church in Aurora, Illinois, protecting the rights of migrant workers. In 1978, he joined the Lawyers' Committee for Civil Rights under the Law in Washington, D.C., and in 1982, he launched Human Rights Watch's (HRW) Americas Program. He continued to work at Human Rights Watch for 15 years, becoming their general counsel in 1994.[3] He is also a visiting scholar at American UniversityWashington College of Law'sAcademy on Human Rights and Humanitarian Law, a Professor of Human Rights Law in Residence at the Washington College of Law, and the Faculty Director of the Anti-Torture Initiative at the law school.
From 1996 to 1999, Mendez served as the Executive Director of the Inter-American Human Rights Institute, based in Costa Rica.[2] He then worked as a Professor of Law and Director of the Center for Civil and Human Rights at the University of Notre Dame in the United States from October 1999 to 2004.[5]
In 2001, Mendez began working for the International Center for Transitional Justice (ICTJ), an international human rights NGO. He served as its president from 2004 to 2009 and now is its President Emeritus. In 2014, he was a member of the Open Society Justice Initiative board.[6]
From November 2010 to October 31, 2016, he was the UN Special Rapporteur on Torture.[1] The Center for Human Rights and Humanitarian Law of the Washington College of Law provided its support through the creation of the Anti-Torture Initiative,[7] with the financial support of the Ford Foundation, the Open Society Foundations, and the Oak Foundation.[8]
In December 2021, the United Nations Human Rights Council appointed Mendez as a member of Racial Justice Body, a new mechanism to examine systemic racism and the excessive use of force against Africans and people of African descent by law enforcement worldwide.[12] Mendez is one of three members along with Yvonne Mokgoro of South Africa and Tracie L. Keesee of the United States.
Principles on Effective Interviewing for Investigations and Information Gathering (Méndez Principles)
In 2016, as the Special Rapporteur on torture and other cruel, inhuman or degrading treatment or punishment, Prof. Méndez submitted a thematic report to the United Nations (UN) General Assembly calling for the development of international standards for interviews based on scientific research, legal safeguards and ethical principles.[13] A global Steering Committee of 15 members guided the process of drafting such a document, consulting an Advisory Council comprising more than 80 experts from over 40 countries. In 2021, the Principles on Effective Interviewing for Investigations and Information Gathering -- based on science, law and ethics --was approved by the Steering Committee to realize the call.[14][15] These principles are also referred to as the Méndez Principles to honor Juan Méndez.
United Nations special rapporteurs bear mandates from the United Nations Human Rights Council and may hold the titles special rapporteur, independent expert or special representative of the Secretary-General, and are also referred to simply as mandate-holders.