30 Tainted by Torture: Examining the Use of Torture Evidence | 2018 defence will ‘in principle be irretrievably prejudiced when incriminating statements made during police interrogation without access to a lawyer are used for a conviction’.133 Frequently, once triggered, the procedure takes the form of a mini trial that ultimately results in a decision taken by the judge presiding over the trial about whether or not to admit the evidence. This procedure takes different forms. In Kenya134 and South Africa,135 after a defendant brings a prima facie136 claim that evidence was obtained by torture, a trial-within-a-trial occurs to determine the issue before the evidence can be admitted. This procedure ensures that an accused person can testify on the issue concerning the admissibility of the evidence without the risk of self-incrimination from crossexamination on matters which could influence a finding of guilt. In Mexico, once a defendant has alleged torture, a hearing must be held to analyse the allegation of torture and to assess whether any evidence should be excluded.137 In Thailand, which does not use jury trials, the motion to dismiss evidence is raised during the trial itself. The court is not required to follow a particular procedure and can exercise its discretion by either: (i) making a determination during the trial as to whether the evidence is admissible; or (ii) allowing the evidence to be heard and determining within the judgment whether such evidence is admissible.138 For practical reasons, the courts of first instance often allow the hearing of evidence whose credibility has been called into question and then later make a determination about whether the evidence should be CASE OF THE KOH TAO MURDERS 140 (2014) This highly publicised and criticised case in which two British nationals were murdered on Koh Tao Island raised controversial questions about due process and the admission of ‘torture evidence’. Following their arrest on 1 October 2014, the two defendants (who were both immigrants from Myanmar) were taken to a ‘safehouse’ for interrogation and were not charged until 3 October 2014. The defence claimed, inter alia, that the confessions of the two defendants were obtained by torture.141 On 24 December 2015, the Samui Provincial Court sentenced both defendants to death for premeditated murder. On the claim of torture, the court reasoned in its verdict that these allegations were unlikely as the officers ‘have not previously known the two defendants and have no previous history of personal grudge or disputes with the two defendants’.142 This would seem entirely to have missed the typical reason why torture is carried out by state officials: to obtain confessions or evidence from defendants. In some of the countries examined, a motion to exclude evidence on the basis that it resulted from torture initiates a separate investigative process. In Vietnam, for example, the court or prosecutor must suspend the trial and order a re-examination of the evidence allegedly obtained by torture.143 In Turkey, too, the criminal trial must be put on hold pending an investigation into whether evidence was obtained by torture.144 Although these investigative processes provide an opportunity for an independent examination of the allegations, they can also pose challenges. Imagine, for example, that a defendant is in pre-trial detention and is facing criminal charges for an offence where, upon conviction, they would be released as the prison sentence imposed is equal to the time spent in pre-trial detention (‘time-served’). In that context, the delays created by the investigation may deter them from triggering the procedure to exclude ‘torture evidence’. III.3 The burden of proof Article 15 of the UN Convention Against Torture applies to evidence which is ‘established’ to have been obtained as a result of torture, but who has to prove that the evidence was obtained by torture and to what standard? This is crucial because, if the burden rests entirely with the defendant and the level of proof is too high, the prohibition will effectively lose all meaning. This question has been the subject of a number of important decisions by regional courts and treaty monitoring bodies. According to CASE STUDY A detailed examination of whether these key fair trial standards are being met in the 17 countries examined is beyond the scope of this report. Meaningful comparisons between the procedures that exist in different countries to identify and exclude ‘torture evidence’ are also complicated by considerable national variations in criminal procedure. admitted in order to avoid a full re-trial of the facts should an appellate court order the evidence in question to be heard.139