A "claim of ineffective assistance of counsel can turn on the cumulative effect of all of counsel's actions. To establish a claim of ineffective assistance, a defendant must show that counsel's performance was deficient and that it prejudiced the defense.A claim of ineffective assistance of counsel presents mixed questions of law and fact that are subject to de novo review. You can use ineffective assistance of counsel claims to bring up issues on appeal that you normally cannot bring up. So the question was whether a single error in otherwise unquestioned performance could support the IAC claim in Harris. The first problem is that the. In his petition, Montgomery claimed ineffective assistance of both his trial and appellate counsel. Here, plaintiffs' complaint raises basic ineffective assistance of counsel claims in the nature of Strickland. 4. (i.e. The Court of Appeals held that based on the record, defendant failed to sustain his burden to establish that counsel was constitutionally ineffective. For example, the defendant might allege that counsel failed to object to evidence, request a jury instruction, or call a witness. 2. Standard.