In the 2005 case of Gary Kent Jones v. Linda K. Flowers, et al., the U.S Supreme Court ruled in favor of Jones, a Mississippi inmate who had been convicted for murder and sentenced to death. The court held that his conviction was unconstitutional due to ineffective assistance from his counsel during sentencing phase of trial. His lawyers failed to present mitigating evidence about his background and mental health issues which could have potentially influenced the jury's decision on capital punishment. This ruling emphasized that defendants are entitled to effective legal representation under Sixth Amendment rights even during sentencing phases after guilt has been determined.

The dissenting opinion in the case of Gary Kent Jones v. Linda K. Flowers, et al., argued that the majority's decision to uphold a lower court ruling against Jones was incorrect because it failed to consider important factors related to his claim of ineffective counsel during his trial for murder and robbery charges. The dissent pointed out that Jones' attorney had not adequately investigated or presented mitigating evidence during the sentencing phase of his trial, which could have potentially resulted in a lesser sentence than death. They also noted that this failure by defense counsel constituted deficient performance under Strickland v. Washington standards and prejudiced Jones’ case as there is reasonable probability that outcome would have been different if such evidence were presented at sentencing hearing.