Global Freedom of Expression

Unconstitutionality of the Internal Security Law in Mexico

Closed Expands Expression

Key Details

  • Mode of Expression
    Non-verbal Expression
  • Date of Decision
    November 15, 2018
  • Outcome
    Decision Outcome (Disposition/Ruling), Law or Action Overturned or Deemed Unconstitutional
  • Case Number
  • Region & Country
    Mexico, Latin-America and Caribbean
  • Judicial Body
    Supreme (court of final appeal)
  • Type of Law
    Constitutional Law, Military Order
  • Themes
    National Security
  • Tags
    State of Emergency, Executive Branch, Members of the Legislative Branch, Members of the Judicial Branch

Content Attribution Policy

Global Freedom of Expression is an academic initiative and therefore, we encourage you to share and republish excerpts of our content so long as they are not used for commercial purposes and you respect the following policy:

  • Attribute Columbia Global Freedom of Expression as the source.
  • Link to the original URL of the specific case analysis, publication, update, blog or landing page of the down loadable content you are referencing.

Attribution, copyright, and license information for media used by Global Freedom of Expression is available on our Credits page.

Case Analysis

Case Summary and Outcome

The Mexican Supreme Court of Justice declared the Internal Security Law unconstitutional in response to challenges brought by civil society organizations and institutions claiming the law had negative impacts on the exercise of human rights and the right to social protest. The law effectively expanded the role of the military in responding to civilian protests, investigating crimes, and gathering intelligence. According to the Court, the law not only enabled, but also concealed, the participation of the Armed Forces in public security functions. The Court referred to the jurisprudence of the Inter-American Court of Human Rights to recall that the military may only intervene in civilian security functions under exceptional circumstances, with proportionate actions and  as a last resort.


Different civil society organizations and institutions filed lawsuits against the Internal Security Law in Mexico on the grounds that, if implemented, the Law could have  negative impacts on the exercise of human rights and the right to social protest. Among others, the petitioners also argued that the legislature exceeded their mandate when they regulated matters of internal security.

The law allowed internal security actions, understood as “those performed by federal authorities, including the Armed Forces on their own or in coordination with other orders by the government, aimed at identifying, preventing, attending to, reducing, and containing risks and threats to internal security.”[1]

The law was analyzed by the Supreme Court of Justice of Mexico and was deemed unconstitutional on November 15, 2018, on the grounds the legislature did not have the authority to regulate matters of internal security.

[1] IACmHR, Office of the Special Rapporteur for Freedom of Expression, Annual Report, 2018

Decision Overview

The Court first considered the current security crisis that Mexico is facing given the presence of organized crime groups. According to the Court, the institutional weakness of the State has created an opening for  the Armed Forces to take on public security responsibilities normally carried out by civilian forces.

The Court noted that the executive is the branch authorized to regulate the actions of the Armed Forces. For this reason, the legislature does not have the constitutional authority to regulate the internal security of the State. The Court recalled that the legislative branch should not exceed its power by attempting to regulate issues that other branches are constitutionally authorized to do.

For the Court, the Law under review “distinguishes between internal security and public security functions, even when there is no material difference between them. In this way, the type of security depends exclusively on the authority that carries it out. The activities carried out by the Armed Forces are considered internal security, and the ones carried out by civil authorities, are considered public security,” [p.44]  For the Court this “defraudes” the Constitution since “it allows the regular participation of the armed forces in the function of guaranteeing public safety.”[p.44] The Court noted that the supposed “purpose of the law is to regulate the internal security under the idea that it is an issue subsumed within national security, but in fact it conceals the participation of the Armed Forces in public security functions. The contested law systematizes the permanent participation of the Armed Forces in tasks of federal entities and municipalities, which cannot be other than public security. It claims to regulate one subject when in reality it is regulating another” [p.45]

The Court referred to the jurisprudence of the Inter-American Court of Human Rights [IACtHR] to recall that the use of military forces is allowed to address citizen security problems, as long as it follows a logic of last resort [ultima ratio] and is limited by certain parameters.

The Court indicated that, according to the IACtHR’s case Cabrera García and Montiel Flores v. Mexico, “when granting the Armed Forces with the faculties to restrict personal liberties, it should meet the requirements of strict proportionality in the restriction of a right, it must also respond to a strict criteria of exceptionality and due diligence in the safeguarding of guarantees [conferred under the ACHR]. This should also take into account that the military regime is not consistent with the specific functions of the civil authorities.”[p.47]

When the Armed Forces intervene in security tasks, their participation must be: extraordinary (exceptional and temporary); subordinate and complementary; regulated under the principles of exceptionality, proportionality and absolute necessity; and audited by competent and independent civil institutions.

Based on the above findings, the Supreme Court of Justice of Mexico considered that the extraordinary conditions (exceptional and temporary) were not met in this case. For the Court, this law created a permanent scheme for the participation of the Armed Forces in public security functions. The Court also stated that it was not possible to conclude that the Congress had the power to regulate the Law of Internal Security, because this is a power which had been exclusively conferred to the executive branch. Thus, the Court declared the unconstitutionality of the internal security law in its entirely.

Judge Alfredo Gutiérrez Ortiz Mena, Norma Lucia Piña Hernández and José Fernando Franco González Salas issued concurring opinions. According to Judge Ortíz Mena, the Law of Internal Security did not meet the constitutional and conventional standards developed by the Inter-American Court of Human Rights, which has stated that “the use of force by governmental security forces must be grounded on the existence of exceptional circumstances and should be planned and proportionally limited by the government authorities. In this aspect, the Court has established that force or coercive means can only be used once all other methods of control have been exhausted and failed” [1].

Judge Piña Hernández contended that the law should be deemed unconstitutional as it had several procedural defects causing its nullification. According to the Judge, if the Law were to be declared constitutional, it would seriously contravene the democratic principles.

Finally, Judge González Salas argued that the law did not regulate issues related to internal security, but rather, it granted to the armed forces participation in public security matters, which is an aspect that should be exclusively regulated by the executive. Thus, the Congress had no authority to issue the Law. Judge González Salas added that the permanent use of armed forces is an aspect that directly affects human rights, so its use must be duly argued and motivated. The Judge added that the judgment did not address a comprehensive interpretation of the guidelines that must be observed according to the Constitution, international treaties and the resolutions of the Inter-American Court of Human Rights, particularly those in which Mexico is directly involved. In this regard, in the event that a new legislation is issued, the Congress will have to adhere to the entire international framework of human rights.

[1] IACtHR, Montero Aranguren v. Venezuela, ser. C No. 150 (2006), par. 67.

Decision Direction

Quick Info

Decision Direction indicates whether the decision expands or contracts expression based on an analysis of the case.

Expands Expression

The decision expands the right to freedom of expression because it deemed unconstitutional a law that could suspend the exercise of fundamental rights, including the right of social protest, during the declaration of a state of public emergency in order to deal with public security challenges.

In response to the Supreme Court ruling, Maureen Meyer, Director for Mexico and Migrant Rights at the Washington Office on Latin America (WOLA), issued the following statement: “This Supreme Court ruling is one of the most important of recent years: it’s an acknowledgement that civil institutions are responsible for providing security to a country’s citizens, and that the military is not a police force. Soldiers should not be used as a substitute for police and Mexico’s armed forces shouldn’t be in charge of the country’s domestic security. This law would have cemented the military’s role in patrolling the streets and would have granted them broad power over civil institutions.”

Global Perspective

Quick Info

Global Perspective demonstrates how the court’s decision was influenced by standards from one or many regions.

Table of Authorities

Related International and/or regional laws

National standards, law or jurisprudence

  • Mex., Internal Security Law (2017).
  • Mex., Constitution of Mexico (1917), art. 1.
  • Mex., Const. (1917) art. 29
  • Mex., Const. (1917) art. 16
  • Mex., Const. (1917) art. 89
  • Mex., Const. (1917) art. 129
  • Mex., Const. (1917) art. 2
  • Mex., Constitution of Mexico (1917), art. 6.
  • Mex., Constitution of Mexico (1917), art. 73.
  • Mex., General Law on Transparency and Access to Public Information (2003).
  • Mex., Const. (1917) art. 21
  • Mex., Const. (1917) art. 119

Case Significance

Quick Info

Case significance refers to how influential the case is and how its significance changes over time.

The decision establishes a binding or persuasive precedent within its jurisdiction.

Official Case Documents

Official Case Documents:

Amicus Briefs and Other Legal Authorities


Have comments?

Let us know if you notice errors or if the case analysis needs revision.

Send Feedback