"This Court has repeatedly stated that a decision announcing a new rule of criminal procedure ordinarily does not apply retroactively on federal collateral review. See Teague v. Lane, 489 U. S. 288, 310 (1989) (plurality opinion); see also Linkletter v. Walker, 381 U. S. 618, 639–640, and n. 20 (1965).
Indeed, in the 32 years since Teague underscored that principle, this Court has announced many important new rules of criminal procedure. But the Court has not applied any of those new rules retroactively on federal collateral review. See, e.g., Whorton v. Bockting, 549 U. S. 406, 421 (2007) (Confrontation Clause rule recognized in Crawford v. Washington, 541 U. S. 36 (2004), does not apply retroactively). And for decades before Teague, the Court also regularly declined to apply new rules retroactively, including on federal collateral review. See, e.g., DeStefano v. Woods, 392 U. S. 631, 635 (1968) (per curiam) (jury-trial rule recognized in Duncan v. Louisiana, 391 U. S. 145 (1968), does not apply retroactively).
In light of the Court’s well-settled retroactivity doctrine, we conclude that the Ramos jury-unanimity rule likewise does not apply retroactively on federal collateral review. We therefore affirm the judgment of the U. S. Court of Appeals for the Fifth Circuit."
https://www.supremecourt.gov/opinions/20pdf/19-5807_086c.pdf