[JURIST] The US Supreme Court [official website; JURIST news archive] ruled [opinion, PDF] unanimously Tuesday in Knowles v. Mirzayance [Cornell LII backgrounder; JURIST report] that a lawyer’s recommendation that a criminal defendant withdraw an insanity plea does not constitute ineffective assistance of counsel for purposes of a federal habeas claim. Writing for the Court, Justice Clarence Thomas reasoned:

The law does not require counsel to raise every available nonfrivolous defense. ... Counsel also is not required to have a tactical reason - above and beyond a reasonable appraisal of a claim’s dismal prospects for success - for recommending that a weak claim be dropped altogether. Mirzayance has thus failed to demonstrate that his counsel's performance was deficient.

In addition, Mirzayance has not demonstrated that he suffered prejudice from his counsel's performance.