Khamfeung Thongvanh v. State of Iowa, 938 N.W.2d 2

Khamfeung Thongvanh was convicted of first-degree murder in 1984; his conviction and an earlier postconviction-relief (PCR) application were denied on appeal in 1993.
In 2017 this Court decided State v. Plain, which overruled precedent that required exclusive use of the absolute-disparity test for the underrepresentation prong of the Duren fair-cross-section analysis and allowed multiple statistical methods.
Thongvanh filed a new PCR application in January 2018 relying on Plain, asserting violations of due process, equal protection, and the right to a jury drawn from a fair cross section.
The State moved to dismiss as time-barred under Iowa Code § 822.3 and otherwise procedurally barred; the district court additionally held Plain is not retroactive and dismissed the application for that reason and for failure to show systematic exclusion.
The court of appeals affirmed; this Court granted further review and held Plain constitutes a new ground of law for § 822.3 purposes but does not apply retroactively on collateral review, so Thongvanh’s PCR was dismissed.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether Thongvanh’s Plain-based fair-cross-section claim is time-barred under Iowa Code § 822.3	Plain announced a new ground of law that could not have been raised earlier; filed within three years of Plain, so timely under the § 822.3 exception	The claim is barred by § 822.3 (and the State also argued procedural bars under § 822.8)	Held: Not time-barred — Plain announced a new ground of law that could not have been raised earlier, so § 822.3’s exception applies
Whether Plain applies retroactively to convictions on collateral review	Plain is a new rule that should apply retroactively (Teague watershed exception) or under broader Iowa constitutional principles	Plain is not retroactive; under Teague it is not a watershed rule and Iowa constitutional guarantees do not require broader retroactivity here	Held: Plain is a new rule under Teague but is not a watershed rule and therefore does not apply retroactively on collateral review; Iowa constitutional arguments rejected

State v. Plain, 898 N.W.2d 801 (Iowa 2017) (overruled prior Iowa rule limiting statistical tests for Duren underrepresentation prong)
Duren v. Missouri, 439 U.S. 357 (1979) (established three-part fair-cross-section test)
Teague v. Lane, 489 U.S. 288 (1989) (framework for retroactivity of new rules on collateral review)
Brewer v. State, 444 N.W.2d 77 (Iowa 1989) (applied Teague to fair-cross-section rule and denied retroactivity)
Batson v. Kentucky, 476 U.S. 79 (1986) (unlawful discrimination in jury selection requires reversal; structural-error context)
Schriro v. Summerlin, 542 U.S. 348 (2004) (distinguishes substantive rules, which are usually retroactive, from new procedural rules)