§ 130.75 Course of sexual conduct against a child in the first degree. 1. A person is guilty of course of sexual conduct against a child in the first degree when, over a period of time not less than three months in duration:

(a) he or she engages in two or more acts of sexual conduct, which includes at least one act of sexual intercourse, oral sexual conduct, anal sexual conduct or aggravated sexual contact, with a child less than eleven years old; or

(b) he or she, being eighteen years old or more, engages in two or more acts of sexual conduct, which include at least one act of sexual intercourse, oral sexual conduct, anal sexual conduct or aggravated sexual contact, with a child less than thirteen years old. 2. A person may not be subsequently prosecuted for any other sexual offense involving the same victim unless the other charged offense occurred outside the time period charged under this section. Course of sexual conduct against a child in the first degree is a class B felony.