Mexico should overturn mandatory pre-trial detention: UN experts

GENEVA (5 September 2022) - The United Nations Working Group on Arbitrary Detention urgently calls on Mexico to abolish mandatory pre-trial detention, also known as “automatic preventive detention”, enshrined in the Constitution.

“Mandatory pre-trial detention is contrary to international guarantees for human rights protection, as the jurisprudence of the Working Group has indicated on multiple occasions,’’ said Miriam Estrada-Castillo, the Working Group’s chair-rapporteur. The Inter-American Court and Commission on Human Rights, as well as the Human Rights Committee and the Committee against Torture, have adopted similar conclusions, the expert said.

Under article 19 of the Constitution, the Mexican legal system obliges judges to impose pre-trial detention on all persons accused of specific crimes, which has led to multiple violations of their fundamental human rights, such as the presumption of innocence, due process and equality before the law.

Mandatory pre-trial detention is also contrary to judicial independence and to the duty to legally motivate the reasons for the detention, Estrada-Castillo said. In addition, it seriously jeopardises the right to personal integrity and to not be at risk of torture or cruel, inhuman or degrading treatment. Even if pre-trial automatic detention is established by law, this is not a guarantee that it is not arbitrary.

“One of the most serious consequences of mandatory pre-trial detention has been that many Mexicans spend more than a decade deprived of their liberty, awaiting trial, without sentence and in conditions of serious risk to their lives and personal integrity. It also contributes to prison overcrowding,” Estrada-Castillo said.

Conscious of the public security challenges that the Government is facing, the Working Group reiterated that mandatory pre-trial detention places Mexico in violation of its international obligations undertaken with the International Covenant on Civil and Political Rights.

Overturning automatic pre-trial detention not only is a key step to addressing the problem of arbitrary deprivation of liberty in Mexico, it will also help to reduce overpopulation in the penitentiary system.

The Working Group, since 2018, through its opinions and communications, has insisted to Mexico that it must urgently resolve this structural problem, repeatedly offering the necessary technical assistance to the Government.

Currently, Mexico has a historic opportunity to overturn a harmful measure that has hindered the fundamental rights of thousands of Mexicans for years.


The Working Group on Arbitrary Detention was established by the former Commission on Human Rights in 1991 to investigate instances of alleged arbitrary deprivation of liberty. Its mandate was clarified and extended by the Commission to cover the issue of administrative custody of asylum-seekers and immigrants. In September 2019, the Human Rights Council confirmed the scope of the Working Group's mandate and extended it for a further three-year period. The Working Group is comprised of five independent expert members from various regions of the world: Ms. Miriam Estrada-Castillo (Ecuador; Chair-Rapporteur), Mr. Mumba Malila (Zambia; Vice-Chair); Ms. Elina Steinerte (Latvia); Ms. Priya Gopalan (Malaysia); and Mr. Matthew Gilllett (New Zealand).

Database of the Working Group on Arbitrary Detention.

The Working Group is part of what is known as the Special Procedures of the Human Rights Council. Special Procedures, the largest body of independent experts in the UN Human Rights system, is the general name of the Council’s independent fact-finding and monitoring mechanisms that address either specific country situations or thematic issues in all parts of the world. Special Procedures’ experts work on a voluntary basis; they are not UN staff and do not receive a salary for their work. They are independent from any government or organization and serve in their individual capacity.