The Khmer Rouge regime was notorious for torturing confessions from persons considered to be enemies. The collection of written confessions recovered from Toul Sleng, the most infamous of the Khmer Rouge torture and execution prisons, runs over 40,000 pages. The ongoing trial at the Extraordinary Chambers in the Courts of Cambodia (ECCC) against Nuon Chea, known as “Brother Number Two,” and Khieu Samphan, Head of State during the regime, includes allegations of torture as a part of crimes against humanity, war crimes, and genocide. Both the prosecution and the defense have asked the Trial Chamber to rule on the admissibility of evidence obtained in connection with torture committed by the Khmer Rouge.

The ECCC is mandated to apply international law principles, including the general provisions of the Convention against Torture  (CAT). The goal of the CAT, nearly universally adopted, including by Cambodia, is to eliminate the use of torture and other cruel, inhuman or degrading treatment or punishment. It mandates that torture be prohibited by States Parties and that they prosecute and punish those responsible for torture. In addition, Article 15 of the treaty requires that “[e]ach State Party shall ensure that any statement which is established to have been made as a result of torture shall not be invoked as evidence in any proceeding, except against a person accused of torture as evidence that the statement was made.”

Excluding the use of torture-tainted evidence is intended to eliminate an incentive to use torture to obtain information, to prevent those that torture from benefiting from their actions, and to preserve the integrity of judicial proceedings. The exclusionary rule also recognizes the inherent unreliability of information obtained through torture. The classic application of the exclusionary rule is that a tortured confession cannot be used as evidence to convict the person who has been the victim of torture.

The Trial Chamber briefly addressed the use of torture-tainted confessions in the Case 001 trial against Kaing Guak Eav, the warden of Toul Sleng Prison, when it granted the prosecution request to put 60 torturer-tainted confessions into evidence, stating: “The relevance of these documents is limited to the fact that they were made and, where appropriate, constitute evidence that they were made under torture. They are not admitted for the truth of the contents.” The chamber went further and stated, “if any party wishes to refer to the truthfulness or otherwise of the contents of the confession, it will be necessary first to establish if the confession was made under torture or the threat of torture.” The Trial Chamber applied the same rule in the first trial of Case 002 (002/01) stating that tortured-tainted confessions “cannot be used as evidence or for the basis for questioning. Therefore the Chamber will remind the parties that it will permit no questions on the content of the confession and nor will it use such information in its verdict.”

Neither the prosecution nor the accused at the ECCC are suggesting that evidence obtained by torture be used against persons that were subject to torture. However, both the prosecution and the defendants are asking the chamber to modify its earlier bright line test and allow reference to the substance of some evidence obtained by torture. They assert that they can use evidence contained in or related to tortured confessions for other purposes without violating the exclusionary rule of the CAT. The prosecution argues that evidence contained in tortured confessions can be used if offered as evidence against persons accused of ordering the torture for any reason other than to prove that the crimes admitted to under torture were actually committed. It argues, for instance, that names of persons provided under torture as part of a prisoner’s network of colleagues, the prisoner’s rank or reasons given for arrest, and descriptions of Khmer Rogue policy are all admissible as evidence of Khmer Rouge policy and its practice of using confessions to pursue additional persons or crimes. The prosecution urges that the court generally admit all confessions and related evidence obtained by torture for such ancillary proof purposes and make decisions in its judgment on the admissibility, reliability, and weight to be attributed to such evidence.

In contrast, the prosecution additionally argues that the CAT prevents the accused in Case 002 – alleged to be responsible for ordering torture – from seeking admission of or referring to evidence related to tortured confessions for any purpose.  Any such use, it argues, would allow the accused to benefit from the use of torture in violation of the language and purposes of the CAT. The prosecution asserts that while torture tainted evidence can be used against a person accused of torture – assuming it is shown to be sufficiently reliable – it can never be used to benefit such accused.

The accused argue the complete opposite and assert that the prohibition against use of torture-tainted evidence does not apply to the defendants at all and that the exclusion in the CAT is only intend to prevent the use of such evidence by state authorities against an individual. They argue the exclusion is not intended to prevent use of torture-tainted evidence by individuals in their defense. Nuon Chea’s lawyers assert, for instance, that facts contained in confessions allegedly produced by torture are admissible at trial to help establish the existence of an internal conflict within the regime that constitutes the foundation of his defense. They interpret the rule excluding torture-tainted evidence as requiring only that such evidence cannot be used against an accused and assert that fair trial concerns mandate that such evidence can be used in their defense. The accused argue that torture-tainted evidence adduced by the prosecution cannot be used for any purpose as evidence against them.

The civil parties argue that the CAT and other relevant laws make clear that torture-tainted evidence, including from Toul Sleng and other Khmer Rouge detention centers, are not admissible for any reason by the accused and are only admissible by the prosecution or civil parties as evidence of fact that they were made and that they were make under torture. Like the prosecution, they argue that annotations added to confessions by interrogators and others in the Khmer Rouge hierarchy are not excluded because they were not obtained by torture and that the subsequent use or reference to information in the confessions made by others may be admissible to show Khmer Rouge hierarchy, communications, and implementation of policies.

Jurisprudence from a variety of domestic and international bodies state a clear rule that torture-tainted evidence cannot be used other than for the limited purpose of evidencing that it was obtained through torture.  For instance, in the December 2005 British appeal judgment A and others v. Secretary of State for the Home Department, the judges discussed the inappropriateness of using torture-tainted evidence obtained from an accused even though the torture was allegedly inflicted by a third party outside the control of the British government. An amicus brief submitted to the ECCC Pre-Trial Chamber in the course of the investigation of Case 002 by the human rights groups Amnesty International, International Commission of Jurists, and REDRESS, argued that use of torture tainted evidence for any reason other than the narrow purpose of establishing that torture was used to extract a statement, is a direct violation of the CAT language and principles and demeans the moral integrity of the court. Under the bright line tests articulated by these views the request for consideration by the prosecution and the defense of torture-tainted evidence (other than evidence that is related to torture-tainted evidence but was not secured by torture, such as annotations added to confessions by others or biographical detail provided before the beginning of tortured interrogation) should not be allowed.

However, the above jurisprudence on the exclusion of torture-tainted evidence generally relates to its use in a proceeding involving the person who was the victim of torture or who was implicated in a crime by a victim of torture. That is not the case in the current requests before the ECCC. Here the defense is claiming basic fair trial rights allow them to use the substance of torture-tainted evidence to help establish their defense theory.  While this is arguably not directly addressed in the CAT or the jurisprudence concerning the CAT, it is certainly an aggressive claim – the allowance of which would be a dramatic departure from the general understanding of the exclusionary rule. The prosecution argument that torture-tainted evidence is admissible to show notice or pattern or policy is not as major a departure from evidentiary principles, which generally allow excluded evidence (such as hearsay) to be used for notice or pattern purposes.   However, whether courts, including the ECCC, will be open to chipping away at the broad exclusionary rule limiting the use of torture-tainted evidence is still untested.

It is not clear what the scope of the ruling from the Trial Chamber on the issues raised by the prosecution and the defense will be as there are a variety of evidentiary scenarios described in the party’s arguments, some of which are not squarely before the court at this time. Nonetheless, the arguments of the parties are radically different and raise significant issues of interpretation of the CAT that have not been definitively addressed in international or national jurisdictions. The Trial Chamber’s response to the questions raised and any more general interpretation of limits of the rule excluding use of torture-tainted evidence bear close attention. It may impact not only this case, but also future interpretation of the CAT and use of torture-tainted evidence in a variety of circumstances, including in international tribunals, such as the International Criminal Court, and domestic and international law related to the “war on terror” and “enhanced interrogation” situations.