Unknown-Unknowns and Fair Trial Rights: The Supreme Court’s Materiality/Lost‑Chance Test for Uncollected “Recent Complaint” Evidence

Introduction

In The People (at the suit of the Director of Public Prosecutions) v S.Q. [2023] IESC 8, the Supreme Court of Ireland (Baker J., Dunne, Charleton, O’Malley and Woulfe JJ. concurring) dismissed an appeal against a rape conviction. The appeal centred on an investigative and disclosure lapse: the Gardaí failed to identify, take statements from, or disclose the existence of two individuals—“R” and his girlfriend—who had accompanied the complainant to the Garda Station and, in the girlfriend’s case, sat with her while she made her initial statement. Their involvement surfaced only at the sentencing stage, via the complainant’s victim impact statement.

The appellant contended that this failure deprived him of potentially valuable evidence—namely, “recent (or first) complaint” evidence—bearing on the complainant’s demeanour and consistency, and thereby rendered his trial unfair. The issues raised compelled the Supreme Court to:

Affirm the scope of the State’s duty to seek out, preserve, and disclose evidence (including potentially defence-favourable material), and
Define the correct appellate test where the uncollected evidence was unknown to the defence at trial and consisted of “recent complaint” material with special, limited admissibility.

Summary of the Judgment

The Supreme Court unequivocally held that the Gardaí breached their duty by failing to seek out and preserve the evidence of R and his girlfriend, and to record and disclose their identities and involvement. However, the Court dismissed the appeal, holding that the breach did not render the trial unfair. In reaching that conclusion, the Court:

Rejected the Court of Appeal’s reliance on the “lost evidence” prohibition jurisprudence requiring defence “engagement” with the missing material (a standard ill-suited where the defence could not have known of the witnesses),
Adopted a materiality/lost‑chance approach focused on whether the absent evidence could have offered “any possible assistance to the defence” (DPP v Farrelly) and whether, viewed in context, there was a lost chance of acquittal under s.3 Criminal Procedure Act 1993 (the proviso), and
Emphasised the limited admissibility and typical prosecution-facing nature of recent complaint evidence, the strength of the extant prosecution case (including medical evidence and inculpatory texts), and the defence’s failure to seek directions at sentencing once the issue surfaced.

Accordingly, although a breach occurred, there was no real prejudice to the fairness of the trial nor any lost chance of acquittal. The conviction stood.

Analysis

1) Precedents Cited and Their Influence

Braddish v DPP [2001] IESC 45, [2001] 3 IR 127: The leading authority on the Gardaí’s investigative duty. Hardiman J. articulated that Gardaí must “seek out and preserve all evidence having a bearing or potential bearing on guilt or innocence,” regardless of whether it assists the prosecution or defence. The Supreme Court here reaffirmed that duty and underscored that it is not predicated on the perceived usefulness of the material (paras 23, 32).
Murphy v DPP [1989] ILRM 71: The duty to preserve evidence is bounded by necessity and practicability (proportionality). The Supreme Court acknowledges this limiting principle (para 28), even as it found the failure in this case plainly fell below the standard: the complainant openly attended with two companions, one of whom sat in on the statement; their details were readily available (paras 33–35).
McKevitt v DPP (Supreme Court, 18 March 2003): Reinforces the constitutional duty to disclose material that could help the defence or damage the prosecution (para 24). The Court ties the investigative duty to the continuing disclosure obligation (para 26).
Traynor v Judge Delahunt [2009] 1 IR 605: A prosecutorial assurance of non-reliance is not an adequate excuse for non-disclosure (para 27). This frames disclosure as defendant-centred, not prosecution-centric.
DPP Guidelines for Prosecutors (2019), s.4C Criminal Procedure Act 1967: Reflect the ongoing, evolving duty of disclosure, sensitive to issues as they arise (paras 25–26).
ECtHR: Edwards v UK; Jespers v Belgium: The Court sets the broader fair trial frame: adequate time and facilities to prepare a defence; totality-of-circumstances approach (paras 30, 41).
Lost Evidence/Prohibition line: Z v DPP; Wall v DPP; Savage v DPP; S. Ó C v DPP; DPP v J.D. [2022] IESC 39: These cases impose a high threshold for stopping trials on the basis of missing evidence, requiring applicants to “engage” with and demonstrate a real risk of unfairness (paras 63–66). The Supreme Court distinguishes these: they are predominantly pre-trial prohibition cases; here, on appeal, the defence could not have known the witnesses existed, making an “engagement” requirement illogical and unfair (paras 67–70).
DPP v Farrelly [2012] IECCA 49: Provides the appropriate appellate lens: would the missing evidence have been of “any possible assistance to the defence” (para 73)? This anchors the Court’s materiality/lost-chance assessment in a context-sensitive way, factoring admissibility and relevance.
Brophy [1992] ILRM 709; R v Nazif [1987] 2 NZLR 122; Kribs v R [1960] SCR 400: These delineate the doctrine of “recent complaint”. The Supreme Court recapitulates that such evidence is not proof of the facts; it goes to consistency, is typically prosecution-facing, and is admissible only within narrow confines (paras 46–55).
People (DPP) v Lacy [2005] IECCA 70; In Re Criminal Law (Jurisdiction) Bill, 1975 [1977] IR 129; J. O’C v DPP [2000] IESC 58: Cited for the right to confront witnesses and principles on calling or tendering witnesses in the Book of Evidence and meaningful cross-examination (paras 80–82). The Court stresses the need for an evidential basis for cross-examination; the narrow admissibility of recent complaint evidence defined those bounds here.

2) Legal Reasoning

The Court’s reasoning proceeds in three stages: breach, standard, and prejudice.

(a) Breach of duty to investigate and disclose: The Court was unequivocal: the Gardaí failed to perform their investigative role by not recording details of R and his girlfriend, not asking basic questions about prior disclosures, and not preserving evidence potentially material to trial rights (paras 31–35). Importantly, the Court rejects any suggestion that the complainant bears blame (para 33): she attended openly with companions; the duty lay with the Gardaí to record and follow up.

(b) The correct appellate standard—rejecting a misplaced “engagement” requirement: The Court criticises the Court of Appeal’s transposition of the “lost evidence” prohibition test (requiring an accused to engage with, and show a real risk arising from, missing material) to an appeal where the defence could not have known of the evidence (paras 62–70). In such a scenario, requiring “engagement” is both impracticable and unfair (para 68). Instead, the Supreme Court articulates the proper inquiry on appeal:

Assess the trial as a whole;
Examine the potential role the absent evidence could have played, including its admissibility and scope;
Ask whether there was a “lost chance of acquittal” (s.3 Criminal Procedure Act 1993), and whether the material could have been of “any possible assistance to the defence” (Farrelly) (paras 73–74).

(c) Application—limited admissibility and absence of prejudice: The Court anchors its prejudice analysis in the special nature of recent complaint evidence:

It is not evidence of fact or of the truth of the complaint; it speaks to consistency (Brophy; Nazif) (paras 46–55).
It is typically prosecution-facing, admissible mainly at the prosecution’s instance to show consistency; the defence may only deploy it to expose inconsistencies and ordinarily cannot compel the prosecution to call such witnesses (paras 58–61, 75–81).
Even if statements had been taken, their use would have been confined, and defence leverage would arise only if the complainant denied a prior inconsistent account that could then be proved (paras 77–79).

Against that backdrop, the Court weighs the actual trial record—complainant’s testimony, corroborative medical evidence of trauma, and inculpatory texts from the appellant (“stupid man”, “sorry for everything”, seeking forgiveness) (para 83)—and finds no real likelihood that access to R or his girlfriend would have altered the outcome. The Court also notes a pivotal procedural fact: when the information surfaced via the victim impact statement (pre-sentencing), the defence did not seek an adjournment or directions to take statements. While not determinative, this pragmatic omission tends to confirm that experienced counsel saw little forensic value in such evidence and—consistently with defence practice—would often seek to exclude rather than include recent complaint evidence (para 85).

3) Impact and Significance

(i) Clarified standard on appeal where the defence could not have known of missing evidence: The Supreme Court draws an important line between prohibition cases (pre-trial, high bar, “engagement” requirement) and post-conviction appeals where the defence was unaware of the material’s existence because of State failure. In the latter, imposing an engagement prerequisite is unfair; the correct test is a nuanced, materiality/lost-chance assessment that is sensitive to admissibility and the trial as a whole (paras 69–74).

(ii) Reinforced investigative and disclosure duties: The case fortifies Braddish principles: Gardaí must proactively record and follow up on obvious evidence vectors, including persons who accompany a complainant to the station or are present during a first statement (paras 33–35). This has immediate operational implications for sexual offence investigations, where recent complaint evidence is often a live issue. Failure to do so is a breach, even if it ultimately does not vitiate a conviction.

(iii) Practical guidance for prosecutors and defence:

Prosecutors should ensure investigative teams capture and preserve details of persons who attend with complainants and pursue any first complaint lines of inquiry, recognising the continuing disclosure duty (CPA 1967, s.4C).
Defence teams who learn (even late) of such persons should consider immediate case management applications (adjournment/directions) to take statements. While the Supreme Court did not treat the omission as a waiver, it weighed it as part of the fairness analysis (para 85).

(iv) Substantive refinement of recent complaint doctrine in fairness assessments: The decision emphasises that the admissibility limitations and prosecution-facing nature of recent complaint evidence must shape the prejudice inquiry. In contrast to missing real evidence (e.g., DNA, CCTV), the non-collection of recent complaint material will less readily ground a finding of unfairness, absent a plausible pathway to a prior inconsistency or other tangible defence advantage (paras 71–79).

(v) Equality of arms, yes; automatic quashing, no: The judgment reaffirms equality of arms and disclosure as facets of Article 38.1 constitutional fair trial rights and Article 6 ECHR (paras 19–22, 30). But breach alone does not inexorably quash a conviction. The proviso (s.3 CPA 1993) enables appellate affirmation where no miscarriage of justice or lost chance of acquittal is shown (paras 39–41).

Complex Concepts Simplified

Recent (or first) complaint evidence: In sexual offence trials, this is evidence that the complainant complained at the first reasonable opportunity. It is generally admissible not to prove what happened but to demonstrate that the complainant’s trial testimony is consistent with their earlier account. It is usually helpful to the prosecution. The defence may only use it to expose inconsistencies between accounts.
Lost evidence (prohibition) vs. uncollected/undisclosed evidence (appeal): In prohibition cases (stopping a trial), a defendant must show a real risk of unfairness and typically must “engage” with the missing material to demonstrate materiality. On appeal—particularly where the defence could not have known of the evidence because the State failed to disclose—it is unfair to require such engagement. The court instead asks whether the missing evidence could have helped the defence and whether there was a lost chance of acquittal.
Equality of arms: A facet of fair trial rights recognising the State’s investigative advantage. It yields duties to seek out, preserve, and disclose relevant evidence, including material that might help the defence.
The proviso (s.3 Criminal Procedure Act 1993): Allows an appellate court to uphold a conviction despite an error if no miscarriage of justice occurred—often framed as asking whether there was a lost chance of acquittal when the trial is viewed as a whole.
Materiality/“any possible assistance”: Borrowed from Farrelly, this asks whether the missing evidence could have assisted the defence in any real way, considering admissibility and the issues actually litigated. It is a pragmatic, context-driven filter.

Conclusion

S.Q. is a careful recalibration of fair trial analysis when the State fails to seek out and disclose evidence that the defence could not have known existed—particularly where the missing evidence belongs to the special category of recent complaint. The Supreme Court:

Affirms a clear breach of investigative and disclosure duties by the Gardaí in not identifying and preserving the involvement of R and his girlfriend,
Rejects the Court of Appeal’s reliance on the prohibition-style “engagement” test in an appellate context where the defence could not have engaged,
Installs a materiality/lost‑chance framework—asking whether the absent evidence could have offered any possible assistance to the defence and whether, taking the trial as a whole, there was a lost chance of acquittal,
Emphasises the narrow admissibility and typical prosecution-facing nature of recent complaint evidence in assessing prejudice, and
Applies the proviso to uphold the conviction given the strength of the trial evidence and the improbability that the missing evidence would have advanced the defence.

The decision provides concrete guidance for investigators, prosecutors, and defence practitioners. For investigators and prosecutors, it is a cautionary tale: record who attends with a complainant, ask about prior disclosure, and preserve that material. For defence, the judgment underscores the value of prompt case-management applications as soon as such gaps emerge. Doctrinally, S.Q. refines the interface between disclosure breaches and appellate review, ensuring that fairness analysis is grounded in admissibility, practical utility, and the totality of the evidence, rather than in formalistic engagement burdens the defence could never have met.