law: Indian Evidence Act, 1872 
  30. Consideration of proved confession affecting person
  
  making it and others jointly under trial for same offence 
  When more persons than
  
  one are being tried jointly for the same offence, and a confession made by one
  
  of such persons affecting himself and some other of such persons is proved, the
  
  Court may take into consideration such confession as against such other person
  
  as well as against the person makes such confession.
   21  [
  
  Explanation—"Offence" as used in this section, includes the abetment
  
  of, or attempt to commit, the offence.]
  Illustrations
  (a) A and B are
  
  jointly tied for the murder of C. It is proved that A said—" B and I
  
  murdered C’ The court may consider the effect of this confession as against B.
  (b) A is on his trial
  
  for the murder of C, There is evidence to show that C was murdered by A and B,
  
  and that B said—"A and I murdered C".
  This statement may not
  
  be taken into consideration by the Court against A, as B is not being jointly
  
  tried.