565.072.  Domestic assault, first degree — penalty. — 1.  A person commits the offense of domestic assault in the first degree if he or she attempts to kill or knowingly causes or attempts to cause serious physical injury to a domestic victim, as the term "domestic victim" is defined under section 565.002.

  2.  The offense of domestic assault in the first degree is a class B felony unless in the course thereof the person inflicts serious physical injury on the victim, in which case it is a class A felony.