The Méndez Principles: The Case for US Legislation on Law Enforcement Interviews

CERL is pleased to present this article (and the entire Just Security series) based on the newly-released Principles on Effective Interviewing for Investigations and Information Gathering, also known as The Méndez Principles. Named for Juan Méndez, the former UN Special Rapporteur on Torture who in 2016 called for the creation of a universal protocol for lawful and humane interviewing standards, the principles provide guidance on conducting non-coercive and rapport-based interviews with legal and procedural safeguards. CERL has been an advocate of Mr. Méndez’s call for the protocol and welcomed him as the keynote speaker at CERL’s 2018 conference on interrogation and torture.–Claire O. Finkelstein, CERL Academic Director


The Méndez Principles: The Case for US Legislation on Law Enforcement Interviews, by Rebecca Shaeffer, was originally published in Just Security.

(Editor’s note: This article is part of a Just Security
series on the newly released “Principles on Effective Interviewing for Investigations and Information Gathering,” an expert-led initiative responding to a 2016 appeal to the U.N. General Assembly by then-U.N. Special Rapporteur Juan E. Méndez to develop such standards. The series outlines the origins and the scientific, legal, and ethical underpinnings of the guidelines, also known as the “Méndez Principles” in honor of its co-chair.)

At a time of collective reckoning for abusive policing in the United States, the conversation is understandably focused on what Americans call “police brutality,” actions that in fact would be recognized in international human rights parlance as “extrajudicial killing” and “torture.” Some Americans are not in the mood for “police reform” that heaps more resources and more training into abusive systems. They instead want to redirect public funds from policing into systems of care. This public sentiment raises questions of whether there is room in the movement for guidance, such as the Méndez Principles, that focuses on effective policing.

But the crisis of police legitimacy in the United States is deeper than the violence caught on bystander videos. It’s not only what police should not be doing (welfare checks that turn violent, traffic stops, consent searches, school security, harassment of marginalized communities), but what they must start doing in order to earn the solemn trust to operate in a democratic society.

For public safety goals to be realized, the United States needs to rationalize law enforcement power and subject it to democratic regulation informed by scientific evidence, public accountability, and transparency. There is increasing appetite not only for the reallocation of police resources but also for safeguards that can help make policing more effective and more ethical. California recently mandated access to counsel in police custody for juveniles, and Illinois banned the use of deception in interrogations of minors. At the federal level, interrogation practices were a topic during a recent hearing of the U.S. House Judiciary Committee on pretrial reform, a sign that there is interest in potential legislation that could play a role.

The primary innovation of the Méndez Principles is to present positive, normative guidance for what police should do in effective and ethical investigations, rather than simply restating the absolute prohibitions against torture and ill-treatment. Telling police what they can’t do doesn’t work. The prohibition of chokeholds in New York City, for example, did not prevent the killing of Eric Garner in a police chokehold.

Comparing U.S. laws and police practice with the Méndez Principles shows how far the United States is from international standards. The vague guidance provided by the Constitution’s 4th and 5th Amendments, repeatedly hollowed out by Supreme Court decisions, does not provide law enforcement with an actionable framework for effective and ethical investigations. Unlike counterparts in some other countries, U.S. police are permitted to lie to and even threaten suspects in interviews, to interrogate even children without a lawyer or family member present, with no clear rules on the conditions of the detention, or the length and nature of the interrogation. Many police units still rely on discredited tactics like isolation and confrontation, which are unsupported by evidence and lead to false confessions and incomplete evidence. Homan Square, the now notorious police detention facility in Chicago, where hundreds of people have been held incommunicado and tortured, still operates with impunity despite efforts to close it, as do police precincts across the country using similar practices.

Declines in Rates of Solving Murders

Abusive practices do not keep the public safe and do not help police solve crimes. The national murder clearance rate in the United States dropped from 95 percent in 1965 to 61 percent in 2020, despite the billions of public funds invested in high-tech forensic labs and military equipment. And clearance rates for murder are far higher than those for other types of crime. However, murder clearance rates are consistently higher in countries where investigative interviewing consistent with the Méndez Principles is used, and where safeguards like the presence of a lawyer during interrogation are implemented.

It may seem counterintuitive that the integration of human rights safeguards and rapport-based interviewing produces better investigative outcomes, but that is exactly what the body of scientific evidence on interviewing shows. When police act in an ethical and trustworthy manner, and when the rights and dignity of people being interviewed are respected, investigative results are more accurate and more comprehensive. Experts point to public trust and cooperation of witnesses as one of the most important factors in solving crime. Abusive practices in U.S. policing are undermining the trust upon which effective law enforcement relies.

Furthermore, the scatter-shot approach that U.S. states and municipalities have taken to reform lays bare the more fundamental problem of a lack of coherent regulation of law enforcement practices across the country. Piecemeal reforms are insufficient to change fundamental norms and cultures without federal leadership. There are good indications that at least some on Capitol Hill realize this. At the recent hearing of the House Judiciary Committee on pretrial reform, witnesses testified to the need for access to counsel in police custody and for regulation of interrogation practices, including banning deception by police and requiring humane treatment of people in custody.

In the face of the U.S. Supreme Court’s failure to insist on true safeguards in police investigation and interrogation, Congress must set standards. One way to advance such norms is by passing federal legislation setting out clear safeguards for interrogations. Although a federal law can only regulate federal investigative authorities and won’t directly impact the archipelago of state and local agencies responsible for the vast majority of investigative interviews, such legislation would help set aspirational benchmarks, develop a body of ethical practice, and contribute to a new articulation of American values in policing and investigations. More fundamentally, it could help demonstrate that all law enforcement powers are subject to democratic oversight and citizen consent, at a time when both civil liability and criminal prosecution of abuses are inadequate to the task.

A Federal Interrogation Bill?

Federal legislation on interrogation could clearly lay out baseline requirements for information-gathering interviews by federal law enforcement that can reduce both rights abuses and criminal litigation, while improving investigative outcomes. These should include:

1. Shoring up the right to counsel: The United States stands apart from other liberal democracies in failing to ensure that arrested people have an attorney with them in custody, prior to and during interrogation. This is especially essential for juveniles and adults with intellectual disability or mental illness, who waive the right to silence and wrongly confess more often than other adults do.

2. Banning deception by law enforcement: Lying to suspects (for example, by telling them that authorities have secured cooperation from a co-accused when this is not true) is not only coercive, it’s generally ineffective and leads to unreliable testimony, and is prohibited in many countries. Norwegian law, for example, specifies that police conducting an interview must “act calmly and considerately” and must not use “promises, incorrect information, threats or coercion.” Improving trust between citizens and the state requires that police be held to an enforced standard of honesty and integrity.

3. Better screening for medical and mental-health vulnerabilities in people who are arrested: Not only would this ensure proper treatment and diversion if appropriate, but it also would allow police to make adjustments to interview styles such that vulnerable people are likelier to provide useful evidence.

4. Ensuring that conditions and interrogation practices respect the basic rights of detainees: People subject to interrogatory interviews should receive regular breaks, meals, and uninterrupted sleep at night. Stress positions and prolonged standing should be clearly outlawed.

5. Mandating audio-visual recording of law enforcement interviews: Electronic recording of the entirety of such interviews, while not a cure-all, carries multiple benefits: discouraging misconduct; preventing disputes and litigation about the content and conditions in which statements are made; and allowing law enforcement authorities to focus on the person they are interviewing, instead of note keeping. Recording of law enforcement interviews is included as a matter of Department of Justice policy, but is still not mandated by federal statute (and only some states require it).

None of these provisions are shocking or new – they have been firmly rooted in international law and practice for decades. But neither are they currently mandated in U.S. law. The United States does not need to reinvent the wheel. The Méndez Principles offer a framework for ethical and effective interviewing that draws on tried-and-tested approaches used effectively for decades in other countries such as the U.K. In order to break out of the cycle of chronic police abuse and ineffective policy responses, the United States needs to focus on building integrity, accountability, and oversight into every stage of law enforcement encounters with the public – even those that don’t end up on viral videos.

(A launch event for the Méndez Principles took place on June 9th featuring speakers including U.N. High Commissioner for Human Rights Michelle Bachelet, Deputy Foreign Minister for Multilateral Affairs of Costa Rica Christian Guillermet Fernández, Ambassadors to the U.N. Mona Juul of Norway and Ramses Joseph Cleland of Ghana, U.N. Special Rapporteur on Torture Nils Melzer, and former U.N. Special Rapporteur on Torture Juan E. Méndez. A recording of the event is available here.)

About the Author

Rebecca Shaeffer

Rebecca Shaeffer (@rebeccashaeffe) is Legal Director for Fair Trials Americas, the DC-based wing of international human rights organization Fair Trials International. She served on the Steering Committee for the development of the Mendez Principles.


CERL is grateful to Steven J. Barela, Senior Research Fellow at the University of Geneva in the Global Studies Institute, for his work in the publication of these articles on The Rule of Law Post. This work, which includes serving as Editor leading the Chairpersons’ Editorial Group of the Méndez Principles initiative, is supported by the Swiss National Science Foundation.

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