Lawyer's Failure to Argue That Defendant Is Mentally Retarded at the Punishment Phase
Moore v. Johnson, 194 F.3d 586 (5th Cir. 1999), was a habeas corpus review of a capital sentence imposed by the State of Texas.
One issue raised was the alleged ineffective assistance of counsel at the punishment phase of the trial.
The Fifth Circuit relied on the Strickland standard: defendant must show that counsel's performance was deficient, i.e., that counsel made errors so serious that he or she was not functioning as the "counsel" guaranteed by the Sixth Amendment, and further must demonstrate prejudice to the defendant from such deficiencies. Id. at 591.
One of the claims was that trial counsel failed to investigate, develop, or present mitigating evidence at punishment, including evidence of organic brain damage, which would have placed petitioner in the mentally retarded classification. Id. at 614-15.
The Fifth Circuit found there to be no conceivable strategy for not investigating and presenting such evidence, id. at 618-19, and that counsel's failure was prejudicial to petitioner. Id. at 619.