What is Circumstantial Evidence?

Legal Definition
Circumstantial evidence is evidence that relies on an inference 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 inference.

On its own, circumstantial evidence allows for more than one explanation. Different pieces of circumstantial evidence may be required, so that each corroborates the conclusions drawn from the others. Together, they may more strongly support one particular inference over another. An explanation involving circumstantial evidence becomes more likely once alternative explanations have been ruled out.

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

Testimony can be direct evidence or it can be circumstantial. For instance, a witness saying that she saw a defendant stab a victim is providing 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 evidence is circumstantial.

Forensic evidence supplied by an expert witness is usually treated as circumstantial evidence. For instance, a forensic scientist may provide results of ballistic tests proving that the defendant’s firearm fired the bullets that killed the victim, but not necessarily that the defendant fired the shots.

Circumstantial evidence is especially important in civil and criminal cases where direct evidence is lacking.
-- Wikipedia
Legal Definition
Evidence that implies a person committed a crime, (for example, the person was seen running away from the crime scene). There must be a lot of circumstantial evidence accumulated to have real weight. Compare to direct evidence.
Legal Definition
The proof of facts which usually attend other facts sought to be, proved; that which is not direct evidence. For example, when a witness testifies that a man was stabbed with a knife, and that a piece of the blade was found in the wound, and it is found to fit exactly with another part of the blade found in the possession of the prisoner; the facts are directly attested, but they only prove circumstances, and hence this is called circumstantial evidence.

2. Circumstantial evidence is of two kinds, namely, certain and uncertain. It is certain when the conclusion in question necessarily follows as, where a man had received a mortal wound, and it was found that the impression of a bloody left hand had been made on the left arm of the deceased, it was certain some other person than the deceased must have made such mark. 14 How. St. Tr. 1324. But it is uncertain whether the death was caused by suicide or by murder, and whether the mark of the bloody hand was made by the assassin, or by a friendly hand that came too late to the relief of the deceased. Id. Vide Circumstances.
-- Bouviers Law Dictionary
Legal Definition
This is proof of various facts or circumstances which usually attend the main fact in depute, and therefore tend to prove its existence, or to sustain, by their consistency, the hypothesis claimed. Or as otherwise defined, it consists in reasoning from facts which are known or proved to establish such as are conjectured to exist. See, more fully, Circumstantial Evidence.
-- Black's Law Dictionary
Legal Definition
Evidence directed to the attending circumstances ; evidence which inferentially proves the principal fact by establishing a condition of surrounding and limiting circumstances, whose existence is a premise from which the existence of the principal fact may be concluded by necessary laws of reasoning. State v. Avery, 113 Mo. 475, 21 S. W. 193; Howard v. State, 34 Ark. 433; State v. Evans, 1 Marvel (Del.) 477, 41 Atl. 136; Comm. v. Webster, 5 Cush. (Mass) 319, 52 Am. Dec. 711; Gardner v. Preston, 2 Day (Conn.) 205, 2 Am. Dec. 91; State v. Miller, 9 Houst. (Del.) 564, 32 Atl. 137.

When the existence of any fact is attested by witnesses, as having come under the cognizance of their senses, or is stated in documents, the genuineness and veracity of which there seems no reason to question, the evidence of that fact is said to be direct or positive. When, on the contrary, the existence of the principal fact is only inferred from one or more circumstances which have been established directly, the evidence is said to be circumstantial. And when the existence of the principal fact does not follow from the evidentiary facts as a necessary consequence of the law of nature, but is deduced from them by a process of probable reasoning, the evidence and proof are said to be presumptive. Best, Pres. 246; Id. 12.

All presumptive evidence is circumstantial, because necessarily derived from or made up of circumstances, but all circumstantial evidence is not presumptive, that is, it does not operate in the way of presumption, being sometimes of a higher grade, and leading to necessary conclusions, instead of probable ones. Burrill.
-- Black's Law Dictionary
Legal Definition
The proof of such circumstances as either necessarily or usually attend facts sought to be proved. See 97 Am. St. Rep. 773, note.
-- Ballentine's Law Dictionary