the appeal may result in a new trial but only if there was some error during the initial trial that meant i didn't receive a fair trial. or if there's new exonerating evidence discovered after the trial that wasn't available before or during the trial.

it's not an easy row to hoe.

most appeals fail. if error is found the appellate court usually deems it harmless and refuses to disturb the verdict or sentence. most successful appeals result in an order for a new trial. and at the new trial when the prosecution has a second chance at the case they often win. again. appeals rarely result in a verdict being overturned out-right and the convict being set free.

the cases we see where convicts are set free on appeal are usually about some sort of malfeasance in the police or court process. like the convict confessed to a crime they didn't commit b/c the police beat the confession out of them. or the prosecutor engaged in misconduct during the trial. or DNA evidence proves someone else committed the offense. those are isolated cases.