Evidence

Any matter of fact that a party to a lawsuit offers to prove or disprove an issue in the case. A system of rules and standards that is used to determine which facts may be admitted, and to what extent a judge or jury may consider those facts, as proof of a particular issue in a lawsuit.

Until 1975, the law of evidence was largely a creature of the COMMON LAW: Evidence rules in most jurisdictions were established by cases rather than by organized, official codifications. Legal scholars long pushed for legislation to provide uniformity and predictability to the evidentiary issues that arise during litigation. Following a lengthy campaign begun by the American Law Institute, which drafted its Model RULES OF EVIDENCE in 1942, and the National Conference of Commissioners on Uniform State Rules, which drafted the Uniform Rules of Evidence in 1953, Congress in 1975 adopted the FEDERAL RULES OF EVIDENCE. The Federal Rules of Evidence are the official rules in federal court proceedings. Most states now also have codified rules of evidence based on these federal rules. Both state and federal rules of evidence serve as a guide for judges and attorneys so that they can determine whether to admit evidence—that is, whether to allow evidence to be observed by the judge or jury making factual conclusions in a trial.

One important benchmark of admissibility is relevance. Federal Rule of Evidence 402 states, in part, "All relevant evidence is admissible, except as otherwise provided." The goal of this rule is to allow parties to present all of the evidence that bears on the issue to be decided, and to keep out all evidence that is immaterial or that lacks PROBATIVE value. Evidence that is offered to help prove something that is not at issue is immaterial. For example, the fact that a defendant attends church every week is immaterial, and thus irrelevant, to a charge of running a red light. Probative value is a tendency to make the existence of any material fact more or less probable. For instance, evidence that a murder defendant ate spaghetti on the day of the murder would normally be irrelevant because people who eat spaghetti are not more or less likely to commit murder, as compared with other people. However, if spaghetti sauce were found at the murder scene, the fact that the defendant ate spaghetti that day would have probative value and thus would be relevant evidence.