circumstantial : Idioms & Phrases

noun evidence providing only a basis for inference about the fact in dispute
indirect evidence.

(Law), evidence obtained from circumstances, which necessarily or usually attend facts of a particular nature, from which arises presumption. According to some authorities circumstantial is distinguished from positive evidence in that the latter is the testimony of eyewitnesses to a fact or the admission of a party; but the prevalent opinion now is that all such testimony is dependent on circumstances for its support. All testimony is more or less circumstantial. Wharton.