(a) A person, other than the victim, commits the offense of failure to report a violent crime committed against an adult if the person, under circumstances not requiring the person to report as required by AS 11.56.765,

(1) witnesses what the person knows or reasonably should know is

(A) the murder or attempted murder of a person by another;

(B) the kidnapping or attempted kidnapping of a person by another; or

(C) the sexual penetration or attempted sexual penetration by another

(i) of a person without consent of the person;

(ii) of a person who is mentally incapable;

(iii) of a person who is incapacitated; or

(iv) of a person who is unaware that a sexual act is being committed; and

(2) does not, as soon as reasonably practicable, report that crime to a peace officer or law enforcement agency.

(b) In a prosecution under this section, it is an affirmative defense that the defendant

(1) did not report as soon as reasonably practicable because the defendant reasonably believed that

(A) doing so would have exposed the defendant or others to a substantial risk of physical injury; or

(B) effective assistance was already being provided by another person; or

(2) acted to stop the commission of the crime and stopped

(A) the commission of the crime; or

(B) the completion of the crime being attempted.

(c) In this section,

(1) “incapacitated” has the meaning given in AS 11.41.470;

(2) “mentally incapable” has the meaning given in AS 11.41.470;

(3) “sexual act” has the meaning given in AS 11.41.470;

(4) “without consent” has the meaning given in AS 11.41.470.

(d) Failure to report a violent crime committed against an adult is a violation.