Many people misunderstand the appeals process in a criminal case. You cannot appeal simply because you lost. You cannot use this process to get a new trial because you did not like the way your first trial went.
According to the United States Department of Justice, an appeal is only for wrongful convictions or unfair sentencing issues, and you must have proper grounds upon which to appeal.
It is essential to understand an appeal is not a new trial but rather a review of the previous trial. You must present something to the appeals court that shows an issue with your first trial. The court will then review the potential errors and make a ruling on them.
The appeals court will also not issue a new sentence. It can send your case back to the lower court for new sentencing, but the appeals court will not give you a new sentence.
Similarly, the appeals court will not make a new ruling either. It may send the case back to the lower court for a retrial to allow you a chance at a new ruling.
Since the appeals court is only reviewing your prior trial, you cannot provide new evidence. The court will not consider it. Instead, you would have to show an error that led to the exclusion of the evidence and hope the appeals court sends your case back to the lower court for a new trial in which you could then introduce the new evidence.
An appeal is simply a way for you to have another court review legal decisions and procedures that occurred during your first trial. It is not a way to provide new evidence or to get a new ruling or sentence in your case.