Circumstantial Evidence

Circumstantial evidence is evidence in which an inference is required to connect it to a conclusion of fact, like a fingerprint at the scene of a crime. By contrast, direct evidence supports the truth of an assertion directly—i.e., without need for any additional evidence or the intervening inference.

On its own, it is the nature of circumstantial evidence for more than one explanation to still be possible. Inference from one piece of circumstantial evidence may not guarantee accuracy. Circumstantial evidence usually accumulates into a collection, so that the pieces then become corroborating evidence. Together, they may more strongly support one particular inference over another. An explanation involving circumstantial evidence becomes more valid as proof of a fact when the alternative explanations have been ruled out.

Circumstantial evidence allows a trier of fact to deduce a fact exists. In criminal law, the inference is made by the trier of facts in order to support the truth of assertion (of guilt or absence of guilt).

Testimony can be direct evidence or it can be circumstantial. If the witness claims they saw the crime take place, this is considered direct evidence. For instance, a witness saying that the defendant stabbed the victim is direct evidence. By contrast, a witness who says that she saw the defendant enter a house, that she heard screaming, and that she saw the defendant leave with a bloody knife gives circumstantial evidence. It is the necessity for inference, and not the obviousness of a conclusion, that determines whether or not evidence is circumstantial.

Forensic evidence supplied by an expert witness is usually circumstantial evidence. A forensic scientist who testifies that ballistics proves the defendant’s firearm killed the victim gives circumstantial evidence from which the defendant’s guilt may be inferred. (Note that an inference of guilt could be incorrect if the person who actually fired the weapon was somebody else.)

On the other hand, the additional circumstantial evidence of the defendant's fingerprint on the trigger would dovetail with this piece to provide corroborating evidence.

The two areas in which circumstantial evidence is of most importance are civil and criminal cases where direct evidence is lacking.