(a) An offender commits the crime of sexual assault in the first degree if

1. (1) the offender engages in sexual penetration with another person

   1. (A) without consent of that person by

      1. (i) the use of force or the express or implied threat of force against any person or property; or
      2. (ii) causing the person to become incapacitated;
   2. (B) by impersonating someone known to the person for the purpose of obtaining consent;
2. (2) the offender attempts to engage in sexual penetration with another person without consent of that person and causes serious physical injury to that person;

3. (3) the offender engages in sexual penetration with another person

   1. (A) who the offender knows is mentally incapable; and

   2. (B) who is in the offender's care

      1. (i) by authority of law; or
      2. (ii) in a facility or program that is required by law to be licensed by the state; or

4. (4) the offender engages in sexual penetration with a person who the offender knows is unaware that a sexual act is being committed and

   1. (A) the offender is a health care worker; and
   2. (B) the offense takes place during the course of professional treatment of the victim.

(b) Sexual assault in the first degree is punishable as provided in AS 12.55 and is

1. (1) an unclassified felony if the offender violates (a)(1)(A), (2), (3), or (4) of this section;
2. (2) a class A felony if the offender violates (a)(1)(B) of this section.