law: 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
  Illustration
  (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.