Roper v. Weaver
In Roper v. Weaver, 127 S. Ct. 2022 (2007), the U.S. Supreme Court issued the rare ruling that "the writ of certiorari is dismissed as improvidently granted." In other words, the Court decided it had made a mistake in granting certiorari in the case, and reversed its own grant of certiorari without ruling on the merits of the case.
The underlying dispute concerned prejudicial remarks made by a prosecutor in obtaining the death penalty. The defendant had filed a petition seeking federal habeas relief before the effective date of the Antiterrorism and Effective Death Penalty Act of 1996 (AEDPA), which a district court had erroneously dismissed. The defendant then refiled it after the effective date of the AEDPA, and the Court of Appeals for the Eighth Circuit held for the defendant despite application of the AEDPA to make these challenges more difficult.
For consistency purposes with respect to similar petitions filed before the effective date of the AEDPA, including one by a co-defendant, the Court sided with defendant and allowed the Eighth Circuit decision to stand.