Code of Federal Regulations Title 25. Indians § 25.11.407 Sexual assault

(1) He or she knows that the conduct is offensive to the other person;  or

(2) He or she knows that the other person suffers from a mental disease or defect which renders him or her incapable of appraising the nature or his or her conduct;  or

(3) He or she knows that the other person is unaware that a sexual act is being committed;  or

(4) The other person is less than 10 years old;  or

(5) He or she has substantially impaired the other person's power to appraise or control his or her conduct, by administering or employing without the other's knowledge drugs, intoxicants or other means for the purpose of preventing resistance;  or

(6) The other person is less than 16 years old and the actor is at least four years older than the other person;  or

(7) The other person is less than 21 years old and the actor is his or her guardian or otherwise responsible for general supervision of his or her welfare;  or

(8) The other person is in custody of law or detained in a hospital or other institution and the actor has supervisory or disciplinary authority over him or her.