Section 20.05. Criminal liability for conduct of another; no defense

In  any  prosecution for an offense in which the criminal liability of
  the defendant is based upon the conduct of another  person  pursuant  to
  section 20.00, it is no defense that:
    1. Such other person is not guilty of the offense in question owing to
  criminal  irresponsibility or other legal incapacity or exemption, or to
  unawareness of the criminal nature of the conduct in question or of  the
  defendant's  criminal  purpose or to other factors precluding the mental
  state required for the commission of the offense in question; or
    2. Such other person has not been prosecuted for or convicted  of  any
  offense  based  upon  the  conduct  in  question, or has previously been
  acquitted thereof, or has legal immunity from prosecution therefor; or
    3. The offense in question, as defined, can be  committed  only  by  a
  particular class or classes of persons, and the defendant, not belonging
  to  such  class  or  classes,  is  for  that reason legally incapable of
  committing the offense in an individual capacity.