Circumstantial evidence is indirect evidence that does not directly prove a fact in issue but gives rise to a logical inference that the fact exists. It requires drawing additional reasonable inferences to support the claim. Circumstantial evidence is especially important when there is little or no direct evidence.

Circumstantial evidence is used in both civil and criminal courts to establish or refute liability or guilt. In criminal cases, most of the evidence used is circumstantial. Common examples of circumstantial evidence include evidence that establishes a motive, evidence of an opportunity to commit the offense, evidence of the accuseds state of mind when the offense was committed, and evidence of the accused preparing for the crime.

Circumstantial evidence is usually the most common form of evidence in product liability cases and road traffic accidents. Forensic evidence supplied by an expert witness is usually treated as circumstantial evidence. For example, a forensic scientist or forensic engineer may provide results of tests indicating that bullets were fired from a defendants gun, or that a car was traveling over the speed limit, but not necessarily that the defendant fired the gun or was driving the car.

Circumstantial evidence is not less valuable than direct evidence, and either type of evidence may be enough to establish guilt beyond a reasonable doubt, depending on the facts of the case as the jury finds them to be. However, the courts are careful when the only evidence in a case is circumstantial evidence, and it should be looked at together with other evidence. A court would be very slow to convict a defendant based on one piece of circumstantial evidence.