Section 210.20. Perjury; pleading and proof where inconsistent statements involved

Where  a  person  has  made  two  statements  under  oath  which   are
  inconsistent  to the degree that one of them is necessarily false, where
  the  circumstances  are  such  that  each  statement,   if   false,   is
  perjuriously   so,   and  where  each  statement  was  made  within  the
  jurisdiction of this state and within  the  period  of  the  statute  of
  limitations  for  the  crime  charged,  the  inability  of the people to
  establish specifically which of the two statements is the false one does
  not preclude a prosecution for perjury,  and  such  prosecution  may  be
  conducted as follows:
    1. The indictment or information may set forth the two statements and,
  without  designating  either,  charge  that  one  of  them  is false and
  perjuriously made.
    2. The falsity of one or the  other  of  the  two  statements  may  be
  established by proof or a showing of their irreconcilable inconsistency.
    3.  The  highest  degree  of  perjury  of  which  the defendant may be
  convicted is determined by hypothetically assuming each statement to  be
  false  and  perjurious.  If under such circumstances perjury of the same
  degree would be  established  by  the  making  of  each  statement,  the
  defendant  may  be  convicted  of  that  degree  at  most. If perjury of
  different degrees  would  be  established  by  the  making  of  the  two
  statements, the defendant may be convicted of the lesser degree at most.