466 U.S. 668 (1984) Cited 159,583 times 179 Legal Analyses
Holding an "error by counsel" doesn't "warrant setting aside the judgment of a criminal proceeding" where in the context of the whole proceeding the identified error "had no effect on the judgment"
501 U.S. 722 (1991) Cited 26,359 times 49 Legal Analyses
Holding in relevant part that federal habeas review of a procedurally defaulted claim is barred "unless the prisoner can demonstrate cause for the default and actual prejudice as a result of the alleged violation of federal law"
538 U.S. 500 (2003) Cited 5,906 times 2 Legal Analyses
Holding that failure to raise an ineffective assistance of counsel claim on direct appeal does not bar a defendant from bringing the claim in a later, appropriate collateral proceeding
Holding that the ineffectiveness prong of Strickland is a high bar, requiring a showing that “no competent counsel would have taken [the action in question]”
Holding that the petitioner was entitled to habeas corpus relief because of "counsel's failure to investigate, obtain, or present any evidence of mitigating circumstances to the sentencing jury"