Méndez Dardón has worked to strengthen access to justice and promote human rights in Guatemala, Honduras, and El Salvador, with a range of civil society organizations including think-tanks and grassroots groups, international bodies, and government institutions. In 2010, worked for Instituto de Estudios Comparados en Ciencias Penales de Guatemala leading the implementation of training processes for judges on the recently created Law Against Femicide and other forms of violence against women. In 2012, as a project coordinator for Iniciativa Social para la Democracia in El Salvador, she created a Citizen Observatory on Access to Information for the Legislative Branch.
Member of the Latin-American roster for the Regional Hub of United Nations Development Program and consultant for UN Women in Honduras on access to justice and citizen security for women projects.
In 2013 Méndez Dardón was appointed as under-secretary of strategic and private affairs to Guatemala’s first female attorney general, Claudia Paz y Paz. During this time, many high-impact transitional justice cases of gross human rights violations were prosecuted. In addition, she has litigated strategic human rights cases before international bodies. As a volunteer for the Robert F. Kennedy Center for Human Rights and The Consejo de Comunidades Étnicas Runujel Junam (CERJ), she has assisted with a forced disappearance case at the Inter-American Commission on Human Rights.
She served as special projects officer to the UN-backed International Commission against Impunity in Guatemala in charge was in charge of the implementation of the UN-Peace Building Fund Project: Consolidation and Decentralization of Strategic Criminal Prosecution within the Public Prosecutor´s Office (MP) to transfer capacities from CICIG to the MP, particularly by establishing clear investigative models, training methodologies, and human resources/administrative systems that meet international standards and certifications.
A frequent contributor to El Periódico. Co-author of Mujeres Ante los Tribunales de Fuero Especial an examination of women who were illegally detained by military forces during the dictatorship of Efrain Rios Mont (Guatemala 1982-1983).