If you have been convicted of a crime, you have the right to ask a higher court to look at various aspects of your case for legal error. The error might have to do with the conviction or the sentence that was imposed.
The goal by the appellant -- which what the defendant is now called -- is to have the case dismissed or retired or have a new sentence imposed. The court will review the case, but it does not look at new evidence. It looks at the court reporter's transcripts, which contain everything that was said in court. In addition, the items admitted into evidence, such as objects or documents, is also considered part of the court record. Written briefs are filed by both sides of the case.
The appellant will file an opening brief, which explains why the conviction should not have occurred or while the sentences were wrong. The government will then file a brief as to why the conviction and/or sentence should stand. The appellant will have an opportunity to file another brief. Both sides may present an oral argument, depending on the appellate court.
An appeal can take several months to be heard and a ruling given. However, the appellant usually has a short time to notify the courts that he or she plans to appeal.
It is your right to appeal an unfavorable verdict. If you have recently been convicted of a crime and feel that there were errors in your trial, it is in your best interests to speak to your attorney about appealing your conviction or sentence.
Source: FindLaw, "Criminal Appeals Overview," accessed Jan. 19, 2016