Evidence (law)

Lore & Background

The law of evidence has ancient roots. Hammurabi's Code required oaths and witnesses, and the Old Testament demanded at least two witnesses for conviction. Ancient Roman law allowed judges freedom to evaluate evidence but insisted that proof is incumbent on the party who affirms a fact, not on him who denies it, and that no one should be convicted on suspicion. Medieval Roman law developed an elaborate grading of degrees of evidence, building on the Biblical two-witness rule, concluding that a single witness or private documents could constitute half-proof, which might justify torture to extract further evidence.

Reader's Guide

A distinct feature of English common law historically was the role of the jury as a finder of fact, as opposed to the role of the judge as finder of law. The creation of modern jury trials in the 16th and 17th centuries necessitated rules of evidence to regulate what testimony and other evidence could be put before the jury. The United States has a very complicated system of evidentiary rules, with some legal experts arguing that the complexity arises from the right of American defendants to have findings of fact made by a jury in practically all criminal cases as well as many civil cases, and the widespread consensus that tight limitations on the admissibility of evidence are necessary to prevent a jury of untrained laypersons from being swayed by irrelevant distractions. The law of evidence remains a central component of legal systems, with ongoing debates about relevance, hearsay, and the role of expert testimony.

Did You Know?

• The Old Testament demanded at least two witnesses for conviction of a crime.
• Medieval Roman law concluded that a single witness could constitute half-proof, which might justify torture to extract further evidence.
• In England, hearsay evidence was historically excluded because the jury were the sole judges of the fact, and no one could tell what effect it might have upon their minds.