Federal Rules of Evidence
body of procedural rules governing the use of evidence in both civil and criminal cases in federal courts. The rules establish the methods by which evidentiary information may be presented, covering such elements as relevance, admissibility, competency of witnesses, privileges, confessions and admissions, expert testimony, physical evidence, and authentication. The rules of evidence have been founded on both case law and state statutes and are shaped by understandings of what constitutes admissible and sufficient proof. Many states have patterned their rules of evidence after those of the federal courts.