What is Circumstantial Evidence?
Circumstantial Evidence is indirect evidence that seeks to prove certain facts by proving other circumstances and events. Direct evidence, such as the testimony of any eyewitness to a particular happening, goes to the precise question in issue. Circumstantial evidence is evidence that, according to the common experience of mankind, usually and reasonably tends to establish the truth of the principal fact in issue, by offering proof of collateral or supporting facts. Thus, evidence that a piece of rock embedded in a wrapped loaf of bread is the same type of rock as that found in the immediate vicinity of a bakery is circumstantial evidence that reasonably tends to establish the principal fact that the stone found its way into the bread during manufacture, leading to the conclusion that the bakery was negligent.
The distinctions between the two types of evidence have developed over many years in the history of Anglo-American law. These distinctions have been defined in case law, that is, in the course of court rulings on the acceptability of evidence in particular trials, and also sometimes by statute.
Despite a popular tendency to look down on the quality of circumstantial evidence, the law gives it weight equal to that of direct evidence. Properly presented, circumstantial evidence may be as conclusive in its power to convince as the direct testimony of an eyewitness. However, the collateral facts in circumstantial evidence must be consistent with the main fact sought to be proved and must be inconsistent with any other reasonable theory. For example, in a prosecution for murder by poison, the facts are often established by such circumstantial evidence as proof of earlier, similar unexplained deaths in the same household; the presence of abnormally large quantities of poison in the victim's body (testified to by toxicological experts); and recent purchase by the accused of quantities of poison. However, proof that poison had long been used to kill rodents, in the accused person's home would be inconsistent with the inference of guilt from the accused's purchase of poison. Thus, such proof required that his purchases of poison be rejected as evidence of homicide.