[header] How to file a motion for a new trial [title] Analyze your case. [step] You must check your state's laws and rules to understand the reasons for which courts will grant a new trial. [substeps] Federal rules only limit the grounds to those accepted under common law, which means you'll have to do additional research to find out what grounds federal judges in your area tend to accept. 
State rules often list specific grounds for which a motion for a new trial may be granted. To properly review what happened at trial and reference it in your motion, you may need to request a trial transcript.