Indian Evidence Act, 1872
11. When facts not otherwise relevant become relevant
Facts not otherwise relevant are relevant-
(1) If they are inconsistent with any fact is issue or relevant fact;
(2) If by themselves or in connection with other facts they make the existence or non-existence of any fact in issue or relevant fact highly probable or improbable
(a) The question is, whether A committed a crime at Calcutta on a certain day.
The fact that, on that day, A was at Lahore is relevant.
The fact that, near the time when the crime was committed, A was at a distance from the place where it was committed. Which would render it highly improbable, though not impossible, that he committed it, is relevant.
(b) The question is, whether A committed a crime.
The circumstances are such that the crime must have been committed either by A,B,C or D. Every fact which shows that the crime could have been committed by no one else and that it was not committed by either B, C or D is relevant.