To constitute ineffective counsel, a defendant's attorney's performance must have fallen below "an objective standard of reasonableness."[5] Courts are "highly deferential," indulging a "strong presumption that counsel's conduct falls within the wide range of reasonable professional assistance."[6] Strickland permits attorneys to make strategic decisions to emphasize one line of defense over another, so long as they are made "after thorough investigation of law and facts relevant to plausible options."[7] Even incomplete investigations are reasonable to the extent that "reasonable professional judgements support the limitations on investigation."[8]
The performance prong emphasizes that the attorney's performance must have been deficient at the time it was rendered, avoiding "the distorting effects of hindsight."[9] Attorneys therefore cannot be ineffective for failing to anticipate future developments in evidence reliability[10] or future changes in law.[11]
Criminal convictions have been affirmed on appeal even where the defense attorney fell asleep during the prosecutor's cross-examination of the defendant,[12] was heavily intoxicated on alcohol throughout the trial,[13] was in extremely poor health and senile,[14] was mentally ill (and even discussed his delusions in opening argument),[15] or was himself a convicted felon whose sentence included community service in the form of defending accused murderers (despite his lack of experience in such cases).[16]
Nonetheless, the Supreme Court has found notable examples of ineffectiveness. In Rompilla v. Beard, the Supreme Court faulted the defendant's lawyer for not reviewing a file that the attorney knew would be used by the prosecution in the sentencing phase of the trial.[17] In Glover v. United States, a lawyer was held to be ineffective when he failed to object to the judge's miscalculation of the defendant's sentence.[18] In Hinton v. Alabama, the Supreme Court held a lawyer's performance ineffective when he did not request funding for a better ballistics expert, though he was statutorily entitled to do so.[19]
2. Prejudice
The prejudice prong of Strickland requires that the attorney's ineffectiveness resulted in an objectively reasonable probability that the outcome of the proceeding would have been different absent the ineffectiveness.[20] For errors of law, the defendant must also have been "deprived of a substantive or procedural right to which the law entitles him."[21] Serving any length of time in prison longer than a defendant otherwise would have constitutes prejudice.[22]
The Cronic Doctrine
In certain limited circumstances, the defendant need not prove prejudice at all, under the Cronic doctrine. In Cronic, the Supreme Court acknowledged that "affirmative government interference in the representation process" or the lawyer's failure to subject the prosecution's case to "meaningful adversarial testing" could constitute ineffective performance and per se prejudice.[23]
The Cuyler Doctrine
Attorneys may have also been ineffective if they had a conflict of interest that was "inherently prejudicial."[24] Such claims arise under the Cuyler[25] doctrine, which makes prejudice somewhat easier to demonstrate than ordinary Strickland claims. Attorneys may be conflicted when they are simultaneously representing multiple people with potentially adverse interests, previously represented clients who shared confidential information that may now be relevant to the current client's interests, have a personal or financial interest adverse to the client, or are part of a firm or organization that may have interests adverse to a client. Defendants may prevail on a Cuyler claim by showing that an actual conflict existed and that the conflict had an "adverse effect" on the defendant during trial, even if there would not have been a reasonable probability the outcome would have differed.[26]
The McCoy Doctrine
A defendant may also not have to demonstrate prejudice if the attorney made a key decision about the case against the client's wishes, including whether to plead guilty (McCoy v. Louisiana), whether to waive the right to a jury trial, whether to forgo an appeal, or whether the defendant wanted to testify on their own behalf.[27]