Wis. Stat. § 938.39
Disposition by the court of any violation of state law within its jurisdiction under s. 938.12 bars any future criminal proceeding on the same matter in circuit court when the juvenile reaches the age of 17. This section does not affect criminal proceedings in circuit court that were transferred under s. 938.18 .
Wis. Stat. § 938.39
The extension of a previously entered dispositional order due to the juvenile's participation in an armed robbery while subject to the order was not a "disposition" of the armed robbery charge, and the subsequent prosecution of the armed robbery charge in adult court did not violate s. 48.39 [now s. 938.39] or the constitutional protection against double jeopardy. State v. Stephens, 201 Wis. 2d 82, 548 N.W.2d 108 (Ct. App. 1996), 95-2103.