Due Process and Postconviction DNA Testing: Noncontamination Rules Cannot Arbitrarily Bar Reliable Testing

Introduction

Reed v. Goertz (U.S. Supreme Court, Mar. 23, 2026) reached the Court on a petition for certiorari after the U.S. Court of Appeals for the Fifth Circuit rejected death-row prisoner Rodney Reed’s federal constitutional challenge to Texas’s postconviction DNA-testing regime as applied to the murder weapon in his case: the victim’s webbed belt. The Supreme Court denied certiorari. Justice Sotomayor, joined by Justices Kagan and Jackson, dissented from the denial.

The dissent frames the case as presenting a grave due process concern: Texas courts relied on a “noncontamination” understanding of the chain-of-custody requirement in Texas Code of Criminal Procedure Article 64 to deny testing, even though Reed asserted modern DNA methods can yield probative and reliable results notwithstanding contamination. The central issue for the dissent is not merely whether Article 64 is constitutional, but whether the Fifth Circuit failed to address a potentially dispositive, independent argument that the noncontamination requirement—given current DNA capabilities—may be arbitrary and thus incompatible with due process.

Summary of the Opinion (Sotomayor, J., dissenting from denial of certiorari)

Justice Sotomayor would have the Court summarily vacate the Fifth Circuit’s judgment and remand because, in her view, the Fifth Circuit did not meaningfully address one of Reed’s core due process theories: that Texas’s noncontamination requirement “serve[s] no legitimate purpose” in light of current DNA technology and therefore may arbitrarily prevent access to potentially exculpatory testing of the murder weapon.

The dissent stresses the stakes: Reed is under a sentence of death; DNA testing of the belt may identify whether Reed’s DNA or an alternative suspect’s DNA is present; and blocking testing on a rigid contamination rationale may leave an “uncertainty” that the legal system should not tolerate where a “simple DNA test” could resolve it.

Analysis

Precedents Cited

District Attorney's Office for Third Judicial Dist. v. Osborne, 557 U. S. 52 (2009)
The dissent uses Osborne for two linked propositions. First, it foregrounds the Court’s recognition that DNA testing uniquely serves truth-seeking (“unparalleled ability” to exonerate and identify perpetrators). Second, it grounds Reed’s federal claim in Osborne’s framework: when a State creates a postconviction procedure for DNA testing, due process requires that the procedure not be “fundamentally inadequate to vindicate” the state-created liberty interest and that it “compor[t] with fundamental fairness.” Justice Sotomayor’s critique is that a categorical “noncontamination” barrier may be fundamentally unfair if it blocks testing that remains reliable.
Reed v. Texas, 589 U. S. 1239 (2020) (SOTOMAYOR, J., statement respecting denial of certiorari)
This earlier writing is invoked to summarize the alternative-suspect theory and the evidentiary proffer pointing to the victim’s fiancé. It provides context for why DNA testing of the belt matters: the belt may contain the killer’s DNA, and identifying it could resolve the contested narrative of guilt.
Ex parte Reed, 271 S. W. 3d 698 (Tex. Crim. App. 2008)
Cited for the factual premise that strangulation with the belt involved “great force” over several minutes—making it likely that biological material from the assailant would be deposited. That likelihood is central to the dissent’s argument that the requested testing is not speculative and that excluding it demands a strong, non-arbitrary justification.
Reed v. Goertz, 598 U. S. 230 (2023)
The dissent notes this Court previously reversed the Fifth Circuit on timeliness, confirming Reed’s ability to pursue his Article 64 due process challenge via §1983 and returning the case to the Fifth Circuit to address the merits. This procedural history underscores why, in the dissent’s view, the Fifth Circuit’s merits analysis needed to confront each independent due process argument actually presented.
Holmes v. South Carolina, 547 U. S. 319 (2006)
Quoted for the due process principle that evidentiary or procedural rules may violate fairness when they “serve no legitimate purpose” or are “disproportionate to the ends” they supposedly advance. Justice Sotomayor uses Holmes as the doctrinal bridge to Reed’s key contention: if contamination does not meaningfully undermine reliability under modern DNA protocols, then a noncontamination prerequisite may be illegitimate or disproportionate.
Evitts v. Lucey, 469 U. S. 387 (1985) and Wolff v. McDonnell, 418 U. S. 539 (1974)
These cases supply the dissent’s overarching due process lens: due process protects individuals against “arbitrary action of government.” Justice Sotomayor’s point is that blocking access to potentially reliable, exculpatory testing based on an inflexible contamination rationale—without engaging the argument that reliability is preserved—risks arbitrariness.
Herrera v. Collins, 506 U. S. 390 (1993) (O'Connor, J., concurring)
Cited to emphasize the “constitutionally intolerable” prospect of executing an innocent person. While Herrera is not treated as creating a freestanding right to DNA testing, it is used rhetorically and normatively to frame the caution demanded when procedural rules block potentially outcome-determinative innocence evidence in a capital case.

Legal Reasoning

The dissent’s reasoning proceeds in three steps.

Identify the specific due process theory that went unanswered.
Reed advanced three “related, yet independent” arguments in the Fifth Circuit. Justice Sotomayor reads the Fifth Circuit’s decision as addressing only (i) the fairness of attributing evidence-condition problems to the State’s custodianship and (ii) the permissibility of different burdens postconviction versus at trial. What is missing, in her account, is a direct ruling on the first argument: that the noncontamination requirement itself is irrational or arbitrary because modern DNA science can detect, model, and account for contamination.
Connect scientific capability to constitutional arbitrariness.
Reed relied on a forensic-science account (via an amicus brief) that even in “worst-case” contamination scenarios, analysts could still include or exclude suspect DNA profiles with high accuracy. If that is correct, the dissent suggests the State’s asserted interest in reliability is not meaningfully advanced by a categorical noncontamination bar. Under the dissent’s Holmes-inflected view, a rule that blocks reliable truth-producing evidence may be “disproportionate” or serve “no legitimate purpose,” and thus becomes a candidate for a due process violation.
Demand appellate engagement with the independent claim, given the capital posture.
The remedy Justice Sotomayor urges is modest in form but significant in function: a summary vacatur and remand so the Fifth Circuit addresses the “arbitrariness” argument “in the first instance.” The dissent treats that procedural correction as essential because the consequence of non-review is that the State may execute Reed without ever testing the murder weapon for potentially dispositive DNA evidence.

Impact

Because the Court denied certiorari, Justice Sotomayor’s writing does not establish binding precedent. Its likely influence is instead doctrinally persuasive and litigation-shaping in three ways:

Sharper due process scrutiny of categorical “contamination” exclusions.
Future challengers to postconviction DNA regimes may frame restrictions (especially chain-of-custody and contamination requirements) not merely as stringent, but as constitutionally arbitrary when modern testing can yield probative results notwithstanding imperfect evidence handling.
Greater focus on technology-sensitive proportionality.
The dissent implicitly treats DNA technology as evolving the “fit” analysis: a restriction once plausibly tied to reliability may become disproportionate as scientific methods improve. That invites courts to evaluate whether procedural barriers remain justified in light of contemporary forensic practice.
Appellate obligation to address independent arguments in high-stakes procedural due process cases.
The dissent’s procedural critique (failure to address a potentially meritorious independent claim) may be cited by litigants seeking remands when appellate opinions collapse distinct constitutional arguments into one.

Complex Concepts Simplified

Denial of certiorari: The Supreme Court declining to review a lower-court decision; it generally carries no implication that the Court agrees with the lower court.
Summary vacatur and remand: An order wiping out (“vacating”) the lower-court judgment and sending the case back for reconsideration, often because of a procedural or analytical defect.
42 U. S. C. §1983: A federal statute allowing individuals to sue state officials for constitutional violations. Here, it is used to challenge the constitutionality of the State’s postconviction DNA-testing procedures as construed and applied.
State-created liberty interest: When a State creates a legal mechanism (like a DNA-testing statute), individuals may have a protected interest in accessing it in a manner consistent with due process.
Facial vs. as-applied challenge: A facial challenge claims a law is invalid in all (or most) applications; an as-applied challenge claims it is unconstitutional in the specific circumstances of the plaintiff’s case.
Chain of custody / “contamination”: Documentation and assurance that evidence has not been materially altered. “Contamination” refers to the presence of additional DNA from handlers or the environment. The dissent’s key point is that contamination may complicate interpretation but does not necessarily destroy the ability to obtain accurate, probative DNA results.

Conclusion

Justice Sotomayor’s dissent in Reed v. Goertz articulates a technology-aware due process concern: when a State provides a postconviction DNA-testing pathway, courts should not allow rigid contamination-based barriers to operate as an arbitrary blockade against potentially reliable, innocence-bearing testing—especially in a capital case. Even without creating binding law, the dissent lays down a pointed marker for future litigation: due process analysis should squarely confront whether the asserted justifications for denying DNA testing still hold in light of modern forensic capabilities, and appellate courts must address independent constitutional arguments rather than letting them go unanswered.