Key legal question
Whether the canton may impute a partial payment first to costs, allowing conversion of the unpaid fine into arrest.
Extracted holding
No. Imputing the payment first to costs, with the consequence that the fine remained unpaid and was converted into arrest, violates the constitutional ban on debt imprisonment.
Extracted reasoning
Conversion of a fine into arrest is permissible only for the fine itself, not as a means to enforce costs. Earlier federal case law forbids unilateral imputation of payments to costs when that would trigger imprisonment for the fine.