[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 lawyers 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 claims 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.Justices Antonin Scalia, David Souter, and Ruth Bader Ginsburg joined in the opinion as to all except Part II, which held that the California Court of Appeals' decision to deny the ineffective assistance of counsel claim did not violate federal law under Antiterrorism and Effective Death Penalty Act of 1996 (AEDPA) [28 USC §2254(d)(1) text]. The decision overturns a ruling [opinion, PDF] by the US Court of Appeals for the Ninth Circuit [official website].
In addition, Mirzayance has not demonstrated that he suffered prejudice from his counsel's performance.