STATEMENT OF THE INSTITUTE OF HUMAN RIGHTS AND MEDIA concerning the case of Christopher Stephan Payne

The Institute of Human Rights and Media issues this statement concerning Mr Christopher Stephan Payne, a United States citizen who remains deprived of liberty in Japan pending the retrial of his case.

This statement has been prepared on the basis of the judgment summaries of the Chiba District Court dated 9 July 2024 and the Tokyo High Court dated 11 December 2025, the summary of the defence closing argument dated 21 June 2024, information communicated by the defence and the Justice 4 Chris Payne support group, and the media materials identified in the endnotes. The Institute has not conducted an independent evidentiary investigation, does not possess the complete case file or the complete texts of all procedural decisions, and does not determine Mr Payne’s guilt or innocence.

On 9 July 2024, the Chiba District Court convicted Christopher Stephan Payne and sentenced him to eight years’ imprisonment with work, crediting 630 days of pretrial detention against the sentence. The conviction concerned an allegation of forcible sexual intercourse causing injury.

The first-instance court found that DNA-analysis results from material collected from the complainant’s mouth strongly indicated Mr Payne as the perpetrator and that the remaining circumstances did not give rise to reasonable doubt as to his guilt.

On 11 December 2025, the Tokyo High Court set aside the conviction and remanded the case to the Chiba District Court for a new trial. The appellate court found that the first-instance judgment had been issued without a full examination of the admissibility and evidentiary weight of the key DNA analysis performed by Professor Yoshihiro Yamada.

The reversal of the conviction is not an acquittal and does not determine that Mr Payne is innocent. It does, however, confirm that issues relating to the DNA evidence central to the original conviction require renewed and comprehensive examination.

According to information communicated to the Institute by the defence and the Justice 4 Chris Payne support group, the case has returned to the Chiba District Court and the retrial is not expected to begin before spring 2027. Mr Payne remains deprived of liberty.

The original conviction relied substantially on DNA analysis performed by Professor Yoshihiro Yamada, referred to below as the “Yamada Analysis” or “Y Analysis.” The biological material was collected from the complainant’s mouth following the incident. Judicial documents indicate that it was a mixed sample containing the complainant’s DNA and DNA attributed by the prosecution to the perpetrator.

The Chiba District Court found that reproducible autosomal DNA profiles had been detected at 15 of 24 loci. It also found that DNA features not explained by the complainant’s profile corresponded to Mr Payne’s profile. On that basis, the court accepted calculations of the frequency of occurrence of the profile, which—depending on the database and assumptions used—were approximately one in 17 trillion persons, one in 446 quadrillion persons, or, after assuming possible allele dropout, one in 264 billion persons.

These figures are not, in themselves, a probability of guilt. They result from the statistical model applied to the interpretation of a mixed sample. The central question is therefore whether the assumptions used to identify and interpret the components of that sample were scientifically justified.

In its closing argument of 21 June 2024, the defence argued that the mixed sample did not permit full isolation of the perpetrator’s DNA profile. The defence further submitted that a conclusion that Mr Payne’s profile was “not inconsistent” with the sample was not equivalent to a conclusive identification of him as the perpetrator. The Institute records this as a defence submission, not as its own scientific opinion.

During the appeal proceedings, raw electropherogram data were re-analysed using a newer version of the GeneMapper software. The Tokyo High Court stated that the re-analysis detected allele 5.3 at the TH01 locus, which was found in neither Mr Payne’s DNA profile nor the complainant’s DNA profile.

Professor Yamada explained that he treated the signal as noise, including because it was not indicated in the population data on which he relied. The appellate court noted, however, that scientific literature documents the occurrence of allele 5.3 at the TH01 locus. The court therefore identified a question as to the reasonableness of the explanation for excluding that signal.

The court did not determine whether the omission of the signal constituted an unjustified deletion of a genuine allele or whether the signal was an erroneous reading that should not have been classified as an allele. It held, however, that unless this issue was clarified, the Yamada Analysis could not be used as evidence identifying the perpetrator and Mr Payne could not be found to be the perpetrator on that basis.

The appellate court also identified the need for further examination of results at the FGA, D7S820 and D10S1248 loci. It directed that the lower court assess whether the Yamada Analysis was conducted using scientifically reliable methods; whether it may be used as evidence of guilt; whether it should be used with limitations; or whether it may have relevance as evidence favourable to the defendant. The court also indicated that it might be necessary to determine whether Mr Payne’s responsibility, if any, could be established through evidence other than the Yamada Analysis.

The prosecution argued during the appeal that GeneMapper provides an initial automated classification of signals, but that distinguishing an allele from an artefact, such as stutter, can require expert judgment. In the prosecution’s view, modification of an automated classification by an expert does not necessarily constitute improper alteration. The appellate court nevertheless found that the identified issues had not been resolved to a degree that would justify maintaining the original conviction.

The Chiba District Court judgment summary states that the mitochondrial-DNA analysis detected a profile corresponding to the complainant, while Mr Payne’s mitochondrial DNA was not detected. The first-instance court held that the non-detection of Mr Payne’s mitochondrial DNA did not exclude his involvement, referring to the possibility of loss, degradation or non-detection of material attributable to the perpetrator in a mixed sample.

The defence advanced the contrary position. In its closing argument, it submitted that the absence of mitochondrial DNA attributed to Mr Payne was capable of excluding him or, at minimum, materially reducing the weight that could be placed on conclusions derived from other DNA analyses. The Institute identifies this as a disputed issue and does not independently determine its scientific significance.

According to the defence closing argument, several samples were collected from the complainant’s clothing, including samples from three areas on the back of a blouse which, according to the defence, could have contained biological material from the perpetrator. The defence asserted that DNA analysis was conducted on only one of those samples, whereas other potentially relevant samples were not tested. The Institute does not possess the complete collection protocols or laboratory documentation and cannot independently verify this assertion.

Alibi was also disputed. The first-instance court confirmed that at approximately 8:07 p.m. on 11 July 2018, Mr Payne sent messages suggesting that he was at the Village Vanguard store in Shibuya. The defence submitted that he later worked at Tokyo Fight Club and that messages sent later in the evening, including a message at approximately 12:25 a.m., could be relevant to determining his location.

The Chiba District Court nevertheless held that the available material did not clearly establish that Mr Payne was at his workplace at the time of the alleged offence. It also referred to security-camera footage of a person resembling Mr Payne near Ichikawa-Ōno Station at approximately 9:21 p.m., considering that circumstance consistent with the possibility that he had left Shibuya and travelled towards the area of the incident.

According to information communicated to the Institute by persons visiting Mr Payne and by the Justice 4 Chris Payne support group, his lawyers obtained medical records from before his transfer from Tokyo Detention House and provided them to an independent physician. The physician reportedly prepared an opinion to accompany a further bail application. On the basis of one blood-test result, the physician reportedly raised the possibility of hyperthyroidism, consistent with the reported symptoms of elevated heart rate, hand tremors or numbness, irritability and anxiety.

According to the same reports, a basic medical examination after Mr Payne’s transfer to Chiba Prison identified deterioration in vision in his right eye. Mr Payne reportedly made repeated requests for medical consultation because of continuing health concerns. As of August 2026, it was reported that approximately three weeks had elapsed following such a request without a medical appointment. The Institute does not possess the complete prison medical records or an official schedule of medical consultations.

The January 2026 article, “Miscarriage of Justice: Experts Have Questioned DNA Tests Used to Convict American Chris Payne of Sexual Assault in Japan,” published in Number 1 Shimbun, reported, on the basis of statements attributed to Mr Payne’s lawyers, that he collapsed following a significant increase in blood pressure two days after the Tokyo High Court judgment. The article further reported that, on 16 December 2025, Mr Payne vomited blood and experienced bleeding from his mouth and nose before receiving care in the detention-centre infirmary. The same article reported that he had been held in solitary confinement at Tokyo Detention House for nearly four years. The Institute cites those matters as attributed media reporting and accounts attributed by the publication to lawyers and persons connected with the case; it has not independently verified them.

Persons supporting Mr Payne have also stated that he suffered frostbite to his fingers during a previous period of detention in Chiba and that he continues to experience nerve damage. This information requires confirmation through relevant medical documentation.

According to the defence, courts denying bail referred to Article 89 of Japan’s Code of Criminal Procedure, which regulates exceptions to mandatory bail. The defence has also referred to provisions allowing discretionary bail and the lifting of detention or release on bail where detention has become excessively prolonged.

According to information communicated to the Institute by the defence, a package of measures was proposed to reduce risks of flight or interference with proceedings: GPS electronic monitoring, a substantial financial guarantee, deposit of travel and identity documents with counsel, a specified residence, personal and video supervision, communication restrictions, and measures addressing immigration status. The applications for release were refused.

The Institute does not possess the complete written reasons for all bail decisions and does not assess their legal correctness. It notes, however, that pending a retrial whose date is not currently known, the necessity and proportionality of continued detention, as well as the practical usefulness of available alternative safeguards, require particularly careful and individualised consideration.

The case engages standards reflected in the Universal Declaration of Human Rights, in particular Articles 3, 5, 9, 10 and 11, and in the International Covenant on Civil and Political Rights, especially Articles 7, 9, 10 and 14. These include the rights to liberty and security of person, a fair hearing, the presumption of innocence, humane treatment of persons deprived of liberty, and the right to defence.

Where an appellate court finds that central evidence requires further, in-depth examination and cannot, at the present stage, be used to identify the perpetrator, particular importance attaches to ensuring that a retrial is conducted fairly, transparently and without avoidable delay.

Critical examination of an individual proceeding is not an attack on Japan, its culture or its institutions. Transparency, independent scientific assessment of evidence and willingness to review earlier decisions serve the credibility of every justice system.

The Institute of Human Rights and Media does not prejudge the outcome of the retrial. It considers, however, that the available judicial materials and the information identified above justify public attention and careful monitoring of the further proceedings.

The Institute calls upon the competent authorities to:

Ensure a prompt, fair and transparent retrial.

Fully clarify the DNA issues identified by the Tokyo High Court, in particular the TH01 locus and the FGA, D7S820 and D10S1248 loci.

Ensure that the defence has meaningful access, within the limits of procedural law, privacy protection and the rights of third parties, to material necessary for a substantive assessment of the DNA evidence.

Conduct an individualised and adequately reasoned assessment of the need for continued detention and of available alternatives, including conditional release subject to supervision.

Ensure prompt and adequate access to medical assessment, treatment and relevant medical documentation, as permitted by law.

Make the reasoning of decisions affecting liberty available to the greatest extent permitted by law.

The Institute also calls on journalists and media organisations to report on the case in a source-based, balanced and responsible manner, respecting the dignity and rights of both the complainant and the defendant. Responsible reporting should enable examination of the positions of the defence, the prosecution, independent experts and public authorities, while clearly distinguishing judicial materials, the parties’ claims, expert opinions and information provided by support organisations.

This statement is informational in nature and constitutes an appeal for transparency, fairness of proceedings and respect for human rights. It does not establish facts for the purposes of criminal procedure, replace expert evidence or substitute for judicial determination.

The Institute of Human Rights and Media does not determine the guilt or innocence of Christopher Stephan Payne. Information derived from the defence closing argument, communications with the support group, health-related reports and media materials is included as the position or report of the identified source. Statements concerning the reasons for reversal of the 2024 conviction are based on the summary of the Tokyo High Court judgment dated 11 December 2025.

The Institute of Human Rights and Media is an independent Polish non-governmental organisation operating in accordance with the applicable law of the Republic of Poland, relevant international legal and human-rights standards, and its statutory objectives. The Institute acts in the public interest, particularly for the protection of human rights, the right to information, integrity in public life and ethical standards in media activity.

The Institute may undertake interventions, analyses and information-related activities in matters in which it is asked for assistance, provided that such action falls within its statutory objectives and organisational capacity. In its work, the Institute seeks to act diligently, remain faithful to verifiable facts, respect the dignity of all persons, uphold the right to defence and present the positions of all parties objectively. The Institute does not replace judicial authorities or prejudge the outcome of proceedings; its role is to promote transparency, institutional accountability and respect for human rights.

This statement may be quoted and discussed by media outlets, provided that its meaning and context are preserved and that a clear distinction is maintained between findings reflected in judicial documents, the procedural positions of the parties, information provided by the support group and media reporting.

The Institute of Human Rights and Media respectfully asks editors, journalists and other users of this statement to quote it accurately, to avoid excerpts or juxtapositions that may alter its meaning, and to identify the source in full as: Institute of Human Rights and Media.

When publishing a quotation from, or a summary of, this statement, the Institute also asks that the publication indicate that the full text, including its qualifications and identified sources, is available at: www.ihrm.org.pl.

Agata Ogrocka

President of the Management Board

Institute of Human Rights and Media

Chiba District Court, Criminal Division 1, Judgment Summary, dated 9 July 2024. The document summarises the conviction, factual basis, the court’s reasoning concerning DNA analysis, mitochondrial DNA, the description of the alleged perpetrator, alibi evidence and sentencing. It was made available to the Institute in materials supplied by the Justice 4 Chris Payne support group.

Tokyo High Court, Criminal Division 4, Summary of Judgment, dated 11 December 2025, 1:30 p.m. The document summarises the reversal of the Chiba District Court conviction and remand for a new trial. It concerns, among other matters, raw electropherogram data, the TH01 locus, allele 5.3, the FGA, D7S820 and D10S1248 loci, the submissions of the defence and prosecution, and the need for further examination of the evidentiary value of the Yamada Analysis. It was made available to the Institute in materials supplied by the Justice 4 Chris Payne support group.

Counsel for Christopher Stephan Payne, Summary of the Defense’s Closing Argument, dated 21 June 2024, Case No. 2021わ No. 2099, Chiba District Court, Criminal Division 1. The document presents defence submissions on mixed DNA material, interpretation of results, mitochondrial DNA, samples taken from clothing, digital data and alibi. The document states that it was prepared before the July 2024 conviction and that DNA-specific details should be confirmed with Mr Payne’s legal team before public dissemination. It was made available to the Institute in materials supplied by the Justice 4 Chris Payne support group.

Gavin Blair, “Miscarriage of Justice: Experts Have Questioned DNA Tests Used to Convict American Chris Payne of Sexual Assault in Japan,” Number 1 Shimbun, Foreign Correspondents’ Club of Japan, January 2026. The media report includes accounts and statements attributed, among others, to lawyers, forensic DNA consultant Dr Simon Ford, Professor Katsuya Honda, Christopher Payne and other individuals connected with the case. It is used in this statement solely as a source of attributed media reporting, including on health and detention-related matters.

Elizabeth Beattie, “American Man Found Guilty of Sexual Assault Fights Ruling Over DNA Evidence,” The Japan Times, 6 March 2026. The article reports on the December 2025 Tokyo High Court ruling, the background of the case, public statements by family members and reported concerns regarding the DNA evidence. This statement relies primarily on source for the reasons behind the reversal of the conviction.

CBS News Chicago, “Northwest Indiana Man Trapped in Japan for Four Years, Fighting to Clear His Name,” 27 April 2026. The report contains statements attributed to forensic DNA consultant Dr Simon Ford and other persons connected with the case, including statements regarding electropherograms, repeated testing, the original description of the alleged perpetrator and the significance of the DNA evidence. Any reliance on this report should remain expressly attributed to CBS News Chicago or the quoted person; it does not constitute an independent finding of the Institute.

Innocence Project Japan, “Chris’ Case,” organisational webpage, accessed in 2026. The page presents the organisation’s and defence-side account of the case, including claims concerning raw DNA data and the Yamada Analysis. As Innocence Project Japan is an organisation involved in support and advocacy for Mr Payne, its information should always be presented as the organisation’s or defence-side position, not as independently verified facts.