Thе Court of Appeals for the Third Circuit granted respondent federal habeas corpus relief from his death, sentence. 271 F. 3d . 527 (2001). Applying the Antiterrorism and Effective Death Penalty Act of 1996 (AEDPA) standard of review,
1
the Court of Appeals concluded that the Pennsylvania Supreme Court, had unreasonably applied federal law in evaluating respondent’s claim that his penalty phase jury instructions and verdict forms were improper under
Mills
v.
Maryland,
*268 Respondent, George Banks, was convicted of 12 counts of first-degree murder stemming from a series of shootings on Sеptember 25, 1982. During the penalty phase of his trial, the jury was instructed, in part:
“The sentence you impose will depend upon your findings concerning aggravating and mitigating circumstances. The Crimefs] Code in this Commonwealth provides that the verdict must be a sentence of death if the jury unanimously finds at least one aggravating circumstance and no mitigating circumstance, оr if the jury unanimously finds one or more aggravating circumstances which outweigh any mitigating circumstance or circumstances.” Commonwealth v. Banks,540 Pa. 143 , 150,656 A. 2d 467 , 470 (1995).
In relevant part, the verdict form required the jury to check a box indicating that “[w]e the jury have found unanimously” either “[a]t least one aggravating circumstance and no mitigating circumstances,” or “[o]ne or more aggravating circumstances which outweigh any mitigating circumstance or circumstances.”
After respondent’s direct appeal was denied, we decided
Mills,
in which we held that the Constitution prohibits a State from requiring jurors unanimously to agree that a particular mitigating circumstance exists before they are permitted to consider that circumstance in their sentencing determination.
Respondent petitioned for federal habeas relief, which the United States District Court for the Middle District of Pennsylvania denied.
The Court of Appeals for the Third Circuit reversed the District Court in part, granting respondent relief from his death sentence under
Mills.
The Court of Appeals first asked: “Are we compelled to conduct a retroactivity analysis under
Teague?”
*270 “Teague teaches that the federal courts habeas corpus proceeding should be reluсtant to apply new rules of federal jurisprudence in state court cases decided before such new rules were handed down. Principles of comity and finality counsel that we maintain a circumscribed scope of habeas review. . . Here, however as we have noted, the Pennsylvania Supreme Court applied Mills. We are examining the application of Mills, not because we wish to impose a new rule not considered by the Pennsylvania Supreme Court, but as the court in fact did consider and apply it. In such a situation, Teague is not implicated. Accordingly, we need ask only whether the Pennsylvania Supreme Cоurt’s application of Mills should be disturbed under the AEDPA standards.”271 F. 3d, at 543 (citation omitted).
Freed from performing a
Teague
analysis concerning
Mills’
retroactivity, a question which has created some disagreement among the Federal Circuits,
4
the Court of Appeals asked “whether the Pennsylvaniа Supreme Court determination regarding the constitutionality of the instructions, verdict slip, and polling of the jury involved an unreasonable application of
Mills.”
*271 Petitioners seek a writ of certiorari, arguing that the Court of Appeals erred by not performing a Teague analysis, by applying Mills retroactively to respondent’s case, and by concluding that the state court’s decision was unreasonable under Mills. We find it unnecessary to resolve the latter two of these claims, because we determine that the Court of Appeals committed a clear error by failing to perform a Teague analysis.
In
Teague,
we explained that “[u]nless they fall within an exception to the general rule, new constitutional rules оf criminal procedure will not be applicable to those cases which have become final before the new rules are announced.”
Although the Court of Appeals may have simply overlooked
Caspari,
its opinion can also be read to imply that AEDPA has changed the relevant legal principles articulated in
Caspari,
see
We reverse the Court of Appeals’ holding that
“Teague
is not implicated” by this case,
It is so ordered.
Notes
Title 28 U. S. C. § 2254(d) was mоdified by AEDPA and now provides, in part, that “[a]n application for a writ of habeas corpus on behalf of a person in custody pursuant to the judgment of a State court shall nоt be granted with respect to any claim that was adjudicated on the merits in State court proceedings unless the adjudication of the claim . . . resulted in a decision that was contrary to, or involved an unreasonable application of, clearly established Federal law, as determined by the Supreme Court of the United States.”
We also grant respondent’s motion for leave to proceed in forma pauperis.
In deciding not to conduct a
Teague
analysis, the Court of Appeals “acknowledge[d] further that the Pennsylvania Supreme Court has specifically noted its skepticism regarding the retroactive application of
Mills”
and has disagreed with the Court of Appeals’ resolution of
Mills
claims similar to respondent’s.
Compare
Gall
v.
Parker,
We havе recognized two exceptions to Teague's rule. “The first exception permits the retroactive application of a new rule if the rule places a class of private conduct beyond the power of the State to proscribe, . . . or addresses a ‘substantive categorical guárantele] accorded by the Constitution,’ such аs a rule ‘prohibiting a certain category of punishment for a class of defendants because of their status or offense.’ ”
Saffle
v.
Parks,
