Key legal question
Which authority has intercantonal competence to prosecute and judge the accused?
Extracted holding
The authorities of the canton of Jura are competent because the alleged acts were committed mainly in Jura and the adult-procedure rules apply.
Extracted reasoning
Mixed offenses before and after age 18 are governed by adult procedure unless, cumulatively, the investigation began before age 20 and a juvenile measure is likely. Although the first condition was met, a juvenile educational measure was not deemed probable, so adult venue rules applied; under Art. 346 CP the place of action controls.