Wis. Stat. § 939.618: Mandatory minimum sentence for repeat serious sex crimes.

(1) In this section, “serious sex crime” means a violation of s. 940.225 (1) or (2).

(2)

(a) Except as provided in par. (b), if a person has one or more prior convictions for a serious sex crime and subsequently commits a serious sex crime, the court shall impose a bifurcated sentence under s. 973.01. The term of confinement in prison portion of a bifurcated sentence imposed under this subsection may not be less than 3 years and 6 months, but otherwise the penalties for the crime apply, subject to any applicable penalty enhancement. The court may not place the defendant on probation.

(b) If a person has one or more prior convictions for a violation of s. 940.225 (1) or for a comparable crime under federal law or the law of any state and subsequently is convicted of a violation of s. 940.225 (1), the maximum term of imprisonment for the violation of s. 940.225 (1) is life imprisonment without the possibility of parole or extended supervision.