§ 140.30  Burglary in the first degree.
  A  person  is  guilty  of  burglary in the first degree when he knowingly
enters or remains unlawfully in a dwelling with intent to  commit  a  crime
therein,  and  when,  in  effecting  entry  or  while in the dwelling or in
immediate flight therefrom, he or another participant in the crime:
  1.  Is armed with explosives or a deadly weapon; or
  2.   Causes physical injury to any person who is not a participant in the
crime; or
  3.  Uses or threatens the immediate use of a dangerous instrument; or
  4.   Displays  what  appears  to  be  a pistol, revolver, rifle, shotgun,
machine gun or other firearm; except that in  any  prosecution  under  this
subdivision,  it  is  an  affirmative  defense  that such pistol, revolver,
rifle, shotgun, machine gun or other firearm was not a loaded  weapon  from
which  a shot, readily capable of producing death or other serious physical
injury, could be discharged.  Nothing contained in this  subdivision  shall
constitute  a  defense  to  a prosecution for, or preclude a conviction of,
burglary in the second degree, burglary in the third degree  or  any  other
crime.
  Burglary in the first degree is a class B felony.