How does a defendant win an appeal?

If the appellate court were to find that prejudicial (unfair) error(s) occurred during the trial, the court would set aside or reverse the conviction, vacate the judgment, and remand, or send back, the case to the trial court for a new trial. The District Attorney decides whether or not to prosecute a new trial.If the appellate court were to find that prejudicial error(s) occurred during sentencing, the court would uphold the conviction but remand the case to trial court for a new sentencing hearing. If the appellate court finds that there was insufficient evidence to support the jury’s verdict, the court would reverse the conviction.