A single instance of ineffectiveness on the part of trial counsel will result in reversal in only a limited number of circumstances. Defining what type of single error should result in reversal is an issue that appears to be still unresolved. For example, in People v. Turner (5 NY3d 476 ), one of the more recent treatments of the subject, the Court of Appeals held that an attorney's failure to raise a valid statute of limitations defense constituted a single egregious instance of ineffectiveness. By contrast, in People v. Hobot (84 NY 2d 1020 ), the court ruled that defense counsel’s single error in failing to review a medical document important to the impeachment of a prosecution witness did not rise to the level of a single instance of ineffectiveness required for reversal (see also, People v. Flores, 84 NY 2d 184 ). After Turner, it remains unclear whether mathematical certainty of success is required to win on the "single egregious error" theory of ineffectiveness or whether some lesser quantum of likely success is required.
Although Turner would seem to suggest that mathematical certainty of success is required, the Fourth Department's decision in People v. Spartacus Brown suggests otherwise. In Brown, the Fourth Department reversed for a single instance of ineffectiveness when, in a prosecution for sexual abuse in the first degree, "defense counsel fail[ed] to object to the admission in evidence of the victim's medical records, which contained information concerning prior allegations of sexual abuse against defendant". This decision is, perhaps, further evidence that the Court of Appeals should clarify its application of the "single egregious error" theory.