The Supreme Court of the United States handed down fourteen per curiam opinions during its 2011 term, which began October 3, 2011 and concluded September 30, 2012.

The Court reversed, for the third time, a judgment of the Ninth Circuit that had set aside the conviction of a woman for the death of her infant grandson attributed to shaken baby syndrome (SBS).

Smith's sentence was subsequently commuted by California Governor Jerry Brown to time served, releasing her after a decade in prison.

The Court considered these efforts unlikely to have made a difference, and "the Sixth Amendment does not require the prosecution to exhaust every avenue of inquiry, no matter how unpromising."

Thomas filed an opinion concurring in the judgment, stating that he believed Texas could implement its redistricting plan regardless of its failure to obtain preclearance in time, because in his view, §5 of the Voting Rights Act is unconstitutional.

The Court reversed the Ninth Circuit's judgment that police officers were not entitled to qualified immunity for entering a private home without a warrant, finding that their belief that violence was imminent, and that a warrantless entry was appropriate, was reasonable under the circumstances.

The District Court entered judgment for the officers, finding that their account of the incident was accurate and ruling that they were entitled to qualified immunity because they reasonably believed that violence was imminent.

Though it accepted the District Court's findings of fact, it instead found that the officers were objectively unreasonable in believing that anyone's safety was at risk, because in their view the mother merely exercised her legal right to end the questioning.

In reversing, the Court criticized the Ninth Circuit for basing its ruling upon a changed version of the facts, as well as for apparently assuming that lawful conduct could not give rise to a legitimate concern that violence was imminent.

The Court also stated that the Ninth Circuit failed to look at the totality of the officers' encounter with the mother, instead incorrectly analyzing each step in isolation.

Finally, the Ninth Circuit failed to give proper consideration to the perspective of the officers at the scene as events were unfolding, instead viewing the case "with the 20/20 vision of hindsight."

Convicted in 1984 and sentenced to death for a robbery, James Lambert filed for habeas corpus due to the discovery of unreleased evidence that the prosecution had failed to disclose to the defense in violation of the decision in Betts v. Brady.

A federal appeals court agreed, vacated Lambert's conviction and ordered him released unless the Commonwealth of Pennsylvania retried him within 120 days.