Day 3: Evidence tainted by torture in law and practice – Challenges, encouraging developments and the role of civil society organisations

Welcome to Day 3!

During the Online Discussion, taking place in the week of 21-25 February 2022, we will publish the written contributions of a number of renowned experts on selected topics concerning the inadmissibility of evidence tainted by torture. We recommend visiting the Online Discussion page this entire week to read diverse perspectives!

Today you can read the contributions of Juan E. Méndez, Anti-Torture Initiative (ATI) as well as Valentina Cadelo and Tomás Pascual, Association for the Prevention of Torture (APT). Amongst others, the contributors feature encouraging developments and discuss the potential of civil society organisations in implementing the exclusionary rule in practice.

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Participating in the discussion:

Pose your questions or share your experiences: Comment on this post. Please also feel free to share your own relevant publications on the topic.

Keeping up to date:

Follow the development of the research, our findings, and insights by regularly checking the Atlas of Torture’s database entries on evidence obtained by torture as well as its Facebook and Twitter.

Disclaimer: The content of the contributions represents the authors’ individual experience and perspective. The opinions stated in these articles are the authors’ own and do not reflect the views of ODIHR or the LBI-GMR.


The exclusionary rule (Article 15 of the UN Convention Against Torture) is an important piece of the elaborate and sophisticated normative framework of International Law surrounding torture and ill-treatment. All my predecessors and my successor as Special Rapporteur on Torture (SRT) have had – like me – multiple occasions to comment on it in country reports and in Observations regarding communications sent to us denouncing instances of torture. Nevertheless, the conventional clause in the CAT contains language that has given rise to equivocal interpretations of the State’s obligation in the presence of evidence possibly obtained by torture, and more seriously has lent itself to bad faith interpretations of the clause.

Challenges in the language of CAT

Article 15 mandates exclusion of evidence that has been determined to have been obtained under torture. This language is deficient because it provides States and authorities with an easy way out: in many countries, courts and prosecutors insist on admitting statements or declarations unless the defendant proves the existence of torture to the court’s satisfaction. This constitutes an unwarranted shift in the burden of proof to the defendant, who is most often in the worst possible position to provide evidence of torture, especially if the defendant is still in custody and without the wherewithal to obtain the services of a qualified forensic doctor. An interpretation in good faith, and consistent with the State’s other due process obligations, would insist that it is up to the prosecution to prove that the statement or declaration and all other means of evidence have been lawfully obtained. In addition, Art. 15 refers only to statements and declarations. In some jurisdictions, evidence that was obtained in a search, seizure or a statement of a second suspect and only indirectly originated from torture is frequently admissible. The object and purpose of the exclusionary rule is not only to provide for a fair trial but also to discourage torture, as stated in the US Supreme Court case called Mapp v. Ohio (Supreme Court of the US, 367U.S.643 (1961)). An interpretation consistent with that object and purpose of the norm would apply the “fruit of the poisonous tree” doctrine and exclude all evidence directly or indirectly related to torture.

In a thematic report on torture-tainted evidence that I presented in my capacity as UN Special Rapporteur on Torture I advocated for this more protective, teleological interpretation of the words of Article 15 (Human Rights Council, Report of the Special Rapporteur on Torture, A/HRC/25/60, 10 April 2014). In addition, Article 15 does not mention torture obtained by methods that constitute cruel, inhuman or degrading treatment, i.e., ill-treatment that does not meet the intensity or specific intent required for torture. For its part, Article 16, in defining that kind of ill-treatment, makes applicable to it various preceding articles, although not specifically mentioning the exclusionary rule. However, the list of other provisions that are applicable to CIDT is preceded by the words “…in particular…”, which can only mean that the list is not meant to be exhaustive. And the provisions of fair trial in general International Human Rights law make it clear that any and all forms of coercion are prohibited and must therefore be subject equally as torture to the exclusionary rule. Regional courts have made this obligation to exclude evidence obtained by means short of torture, albeit with various scopes of application (ECtHR, Gafgen v Germany, 1 June 2010; IACtHR, Cabrera Garcia and Montiel Flores v Mexico, 2010.)

Finally, Article 15 obliges States to exclude evidence obtained by torture in any proceeding against the person making the declaration. Proceeding is a broad concept that refers not only to criminal prosecutions but includes also disciplinary and other administrative processes. There is no question, therefore, that the exclusionary rule applies equally to evidence used, for example, in immigration decisions and in asylum and refugee determinations. In the context of the Global War on Terror, some powerful States took the position that there was no obligation to exclude information obtained under torture if it was not used as evidence in proceedings. For example, in planning intelligence or military operations. Also, that the exclusionary rule applies only to evidence obtained by the State’s own agents, but not to that obtained by intelligence services of other States. Finally, those powerful States also adhered to the notion that all the obligations acquired through ratification of CAT and other human rights treaties were strictly territorial, i.e., that they did not apply to wrongful acts conducted by the States’ agents when operating overseas. Notably, that also left open a wide gate to encourage the practice of torture by their own agents, also in contravention with the object and purpose of the exclusionary rule.

The exclusionary rule in domestic law

It is up to the domestic jurisdiction to establish procedures to give effect to the exclusionary rule through legislation and regulation, and for domestic courts to decide if those procedures comply with constitutional as well as conventional standards. In many countries, however, procedural law is not clear as to what the court has to do if an issue arises as to the possibility that a piece of evidence may have been obtained under torture. In such cases, courts may decide that there is a possibility that torture occurred and pass that along the matter to a prosecutor - where it dies because most prosecutors prefer not to investigate further and file charges against suspected perpetrators. In some countries, courts do not follow up on referral to the prosecutor, claiming that the notion of prosecutorial discretion is part of the sphere of autonomy of the prosecutor’s office and off-limits to judicial supervision. And yet torture is an international crime that obliges the State to investigate, prosecute and punish every incident of torture and ill-treatment. For that reason, exercises of prosecutorial discretion must be judicially reviewable under standards of reasonableness, in order to eliminate or sharply reduce the effects of impunity for torture.

Again on the implementation of the exclusionary rule, courts in many countries receive claims of torture of defendants and perhaps make some effort at corroboration, say by ordering a medical examination to be performed according to Istanbul Protocol standards. But then courts defer the decision on the exclusionary rule to the trial of the defendant. This of course could take several years and, if the crime is serious enough, the defendant would spend that time in preventive detention. A proper application of the exclusionary rule should be prompt, as it is an important way to operationalize the presumption of innocence. If a confession is excluded, the proceedings should continue if backed by other evidence, including the holding of a trial and a decision to convict or acquit. Even if the court eventually acquits by excluding crucial evidence, the person may have spent four or five years in prison on the basis of torture-tainted evidence. It is important, therefore, to conduct an autonomous and prompt investigation specifically on the claim of torture and, if proven, the resulting evidence – and other evidence derived from the mistreatment – must be excluded ab initio.

Encouraging developments

In Mexico, the Supreme Court in 2014 issued a non-binding directive called Protocolo de Actuacion en casos de Tortura that was addressed to lower courts on how to act in cases where torture is alleged or where a magistrate presumed that unlawful methods may have been part of the investigation. This directive was thorough and detailed but its non-binding character probably resulted in a very limited impact in the practice of lower courts. In 2017 the Congress passed a very comprehensive law called Ley General sobre Tortura that, among other things, applies not only in the federal system but is mandatory in all States of the federation (Ley General para Prevenir, Investigar y Sancionar la Tortura y Otros Tratos o Penas Crueles, Inhumanos o Degradantes, 16 July 2017). In November 2021 the Supreme Court issued another directive reasserting the 2014 Protocol, this time with more detailed and complete instructions than in the 2014 directive (Corte Suprema de Justicia, Protocolo para Juzgar Casos de Tortura y Malos Tratos, It is expected that it will result in more practical and expeditious ways for higher courts to supervise and control how lower courts implement the exclusionary rule as well as the obligation to investigate, prosecute, and punish torture.

In Brazil, the Supreme Court also instituted a system of Audiencias de custodia in 2015. It was also done by means of a non-binding directive to State and federal courts below. Significantly, however, in a matter of months several State courts had implemented the system and in later years it has been extended to the whole country. In essence, the practice is now that, within 24 hours of deprivation of liberty, the detained individual has to be brought before a court so that a magistrate can: 1) determine the legality of the arrest; 2) decide whether action is needed regarding detention conditions, interrogation, etc. A doctor is available who can conduct a medical examination under the Istanbul Protocol if a claim of torture is made or if the magistrate has reason to believe that mistreatment has occurred. Despite the fact that, for now, courts continue to accept a broad and questionable standard of flagrante delicto as justification of arrests, the system of custody hearings is by all accounts functioning smoothly and efficiently.

Also in Brazil, the Court of Appeals (Fourth Criminal Chamber) of the State of Rio de Janeiro issued a historic decision on 15 February 2022, in a case known as Sala Vermelha (“Red room”). The decision upheld the lower court acquittal of six young men detained by Army agents in 2018. They had been taken to a military facility upon arrest – for which the Court found no justification in law – and they had confessed to crimes under torture. The appellate decision established clearly that torture had occurred, as had been certified by a lower court in the opportune moment at the custody hearing. In March 2019 all suspects had been reexamined at the Medico-Legal Institute, with the assistance of international forensic experts, at which time the detainees were found to be suffering from post-traumatic stress disorder as a consequence of the torture they had endured.

Juan E. Méndez, Faculty Director of Anti-Torture Initiative

Juan E. Méndez is a Professor of Human Rights Law in Residence at the American University – Washington College of Law, where he is Faculty Director of the Anti-Torture Initiative, a project of WCL’s Center for Human Rights and Humanitarian Law. In January 2022, he began a three-term as a member of the International Independent Mechanism on Racial Justice and Equality in Law Enforcement. Mr. Méndez was the UN Special Rapporteur on Torture and Other Cruel, Inhuman and Degrading Treatment or Punishment between 2010 and 2016. He was the Special Advisor of the Secretary-General on the Prevention of Genocide from 2004 to 2007 and between 2000 and 2003 he was a member of the Inter-American Commission on Human Rights.



The inadmissibility of evidence obtained by torture (also known as the “exclusionary rule”, and found in Article 15 of the UNCAT) is a crucial aspect of States’ obligations to prevent torture. It removes one of the main incentives for law enforcement officials to use torture or ill-treatment – to elicit confession. Further, in the words of the UN General Assembly, the “adequate corroboration of statements, including confessions, used as evidence in any proceedings constitutes one safeguard for the prevention of torture and other cruel, inhuman or degrading treatment or punishment” (GA Res 67/161 of 20 December 2012, para 16).

The main responsibility to ensure implementation of the exclusionary rule lies with the different state institutions, as the State is the primary bearer of the duty to prevent torture. However, many other actors, such as civil society organisations (CSOs), play a critical role in the effective implementation of this rule and, accordingly, further contribute to prevent torture in practice.

Against this background, this blog post provides a few reflections on how CSOs involved in the area of torture prevention may actively contribute to ensure the prohibition of evidence tainted by torture is better applied in law and practice.

Drawing on the experience acquired by the Association for the Prevention of Torture (APT), this contribution highlights the critical role that CSOs play while:

Intervening as a third party in the courts’ review of domestic regimes to ensure compliance with existing standards on the prohibition of evidence tainted by torture and its effective implementation in law and practice; and

Supporting and promoting the development of new, comprehensive and systemic frameworks that concretely assist the effective application of the exclusionary rule in domestic law and practice.

I. Third-party interventions before courts: a unique opportunity for CSOs to promote State compliance with international standards on the exclusionary rule

Third-party interventions constitute an important way for CSOs to engage actively in a dialogue with courts as well as to contribute to the review of domestic regimes that fall short of international standards. Typically, they provide CSOs with the opportunity to submit additional information and/or expand on specific legal issues that are of wide public importance and could have a big impact on the interpretation or protection of human rights law in a country.

Over the past years, the APT actively engaged with courts both at the regional and national level to promote State compliance with international standards on the exclusionary rule. Recent examples include the APT amicus curiae brief presented before the Inter-American Court of Human Rights (IACtHR) in 2010, as well as APT submissions to the Mexican Supreme Court in 2014 and the Costa Rica Constitutional Court in 2017.

While each of the above mentioned submissions holds its own value, the APT amicus curiae brief presented in the IACtHR case of Teodoro Cabrera García and Rodolfo Montiel Flores against the United Mexican States perhaps constitutes one of the most significant examples of how CSOs third-party interventions may effectively contribute to elucidating international standards on the exclusionary rule, and accordingly promote its effective implementation at the national level.

The APT amicus curiae brief provided analysis and comparative law jurisprudence on the duty of States to prevent torture and to ensure that evidence is not obtained through this practice. The document focused on different aspects of the principle of non-admissibility of evidence obtained by torture, including its absolute and non-derogable nature; its purpose and relationship with fair trial rights; as well the burden of proof. Finally, the piece tackled the evidentiary value of confessions, with a particular reference to the principle of procedural immediacy in Mexico.

In its judgement, the IACtHR considered several arguments enclosed in the APT amicus curiae brief. Most importantly, it concluded that Mexico breached Article 8.3 of the American Convention on Human Rights, by not excluding evidence obtained by torture in judicial proceedings (Judgement of 26 November 2010, para. 177). Further, in line with APT’s arguments, the Court stated, “statements obtained under duress are seldom truthful, because the person tries to say whatever is necessary to make the cruel treatment or torture stop”. Consequently, “accepting or granting evidentiary value to statements or confessions obtained by coercion, which affect the person or a third party, constitutes, in turn, an infringement of a fair trial.” Additionally, the Court noted that “the absolute nature of the exclusionary rule is reflected in the prohibition on granting probative value not only to evidence obtained directly through coercion, but also to evidence derived from such action" (Judgement of 26 November 2010, para. 167).

II. CSO-led initiatives that support the effective implementation of the exclusionary rule in practice: a new opportunity for CSO engagement

CSOs can also play a critical role on a broader level, particularly by addressing institutional incentives and other systemic factors that prevent the effective implementation of the exclusionary rule in practice.

As recent research shows, the effective implementation of the exclusionary rule is often tied to how the criminal justice system operates. For instance, criminal justice systems that rely mostly on confessions as the main evidence on which convictions are founded, will most likely face challenges in ensuring effective application of the exclusionary rule in practice. Conversely, criminal justice systems that exclude confession based evidence are likely to be more effective in the implementation of the exclusionary rule.

In this context, the new Principles on Effective Interviewing for Investigations and Information Gathering, also known as the Méndez Principles, are a concrete example of a CSO-led initiative that offers solution-oriented guidance for the effective implementation of the exclusionary rule in domestic law and practice, while addressing existing incentives and other systemic factors that impede the correct functioning of criminal justice systems in line with international standards on torture.

The Principles are the culmination of a four year consultation process led by the APT together with the Anti-Torture Initiative (ATI) and the Norwegian Center for Human Rights (NCHR). The process involved police investigators, academics, human rights lawyers and CSO representatives from all over the world, and the Principles were drafted by a multidisciplinary, gender balanced, and geographically representative group of international experts.

In a nutshell, the Principles aim to move away from coercive and confession-based questioning towards the promotion of rapport-based interviewing combined with the implementation of safeguards during criminal justice investigations and other forms of information gathering processes.

Built on the premise that confession oriented criminal justice systems incur a higher risk of torture, the Principles do not merely reiterate international standards on the inadmissibility of evidence tainted by torture. Rather, they provide concrete guidance on how to implement this rule in practice.

Notably, the Principles state that judicial authorities play an essential role in ensuring the effective implementation of such a rule, thereby calling for the removal of incentives for investigation authorities to obtain a confession by any means and promote the use of ethical and scientifically proven interviewing methods instead. Further, judicial authorities are called upon to ensure that only lawfully obtained evidence is admissible in any proceedings and accordingly to be vigilant to any signs that a statement may have been made under coercion or ill-treatment (Méndez Principles, Principle 6, paras. 218-219).

The Principles also provide for a duty to report where criminal justice professionals see, hear of, or suspect interview-related wrongdoing. Similarly, considering that an over-reliance on confessions in judicial proceedings provides an improper incentive for interviewers to seek confessions as the sole objective, they call for a shift in the ultimate goal of an interview, with the objective being to collect reliable and accurate information and not a confession. (Méndez Principles, Principle 5, paras. 185-187).

Finally yet importantly, the Principles stress that excluding evidence obtained under torture or other ill-treatment is an interviewee’s right and accordingly it constitutes an effective remedy against wrongdoing by interviewers (Méndez Principles, Principle 5, para. 203).


As highlighted in this blog post, CSOs can play a crucial role in ensuring that the rule on the exclusion of evidence tainted by torture is effectively implemented in practice, both by intervening as third parties in judicial proceedings and by leading initiatives promoting new frameworks that best address existing shortcomings in the criminal justice system that prevent its full implementation.

The examples cited here, however, represent only two of many more ways for CSOs to actively contribute to the effective implementation of the exclusionary rule in practice. Due to their independence and vital role in fostering consultative and transparent processes, CSOs are indeed in a unique position to act as traction forces for change and accordingly advocate for necessary reforms in both law and practice.

In this context, discussions such as those organized by ODIHR and the Ludwig Boltzmann Institute of Fundamental and Human Rights are a particularly welcomed step as they provide the perfect opportunity for CSOs to exchange on new ideas with relevant stakeholders, identify potential avenues for cooperation and ultimately bring forward ongoing efforts to prevent torture. In this spirit, the APT looks forward to having a fruitful exchange with all the participants and continue working together on the prevention of torture. #TogetherWeCanEndTorture

Valentina Cadelo ,Senior Adviser, Law and Advocacy at the APT

In that capacity, she leads the APT legal and advocacy work on torture prevention and acts as focal point to requests related to legal issues from relevant stakeholders. Prior to joining the APT, Valentina worked extensively on human rights issues for various NGOs, such as the International Commission of Jurists and Impunity Watch, as well as in the academic sector.

Tomás Pascual , Fellow in Criminal and Judicial Systems at the APT

From 2018, he leads the Human Rights Unit at Criminal Public Defence in Chile incorporating international human rights standards to the defenders’ work and designing and implementing new policies on access to justice for defendants and persons deprived of liberty.


This topic was automatically opened after 4 days.

Thank you Juan, Valentina, and Tomás for contributing to this third day of the Online Discussion “The Inadmissibility of Evidence Tainted by Torture” with your inspiring contributions!

To build on some of the important points you raised, we would like to invite also others to share any additional thoughts:

How can civil society actors actively contribute to the effective implementation of the exclusionary rule in practice?

Fell free to share any ideas, promising practices or success stories from your countries!

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It may be of interest to note also that under the Council of Europe Committee of Ministers Rules NGOs and NHRIs, inter alios, may submit communications on the execution of ECHR judgments whose execution supervision is pending before the Committee - - Rule 9§2: “The Committee of Ministers shall be entitled to consider any communication from non-governmental organisations, as well as national institutions for the promotion and protection of human rights, with regard to the execution of judgments under Article 46, paragraph 2, of the Convention.”


Thank you for that advice - reminded me to share the report from the Council of Europe European NPM Conference: The Role of NPMs in the Effective Implementation of European Court of Human Rights Judgments and CPT Recommendations.


Dear Juan, Valentina and Tomás, my turn to thank you for these excellent contributions.

Looking at the positive examples of Mexico and Brazil highlighted by Juan in his contribution, it would be interesting to see examples from other countries.

Are there some examples in other countries/regions where directives have been successfully implemented by courts?

What does a complete/detailed directive for courts look like to help them enforce the exclusionary rule in practice?

Readers, please feel free to share promising practices!

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