Key legal question
Whether the prosecutor's refusal to take additional evidence at the end of the investigation was appealable directly to the Federal Supreme Court.
Extracted holding
The appeal was not admissible because the challenged evidentiary refusal was an incidental decision that caused no irreparable legal harm.
Extracted reasoning
Evidentiary decisions are generally reviewable only against the final decision; any alleged violation of the right to evidence can be raised against a later dismissal, and the cantonal authority may itself take evidence or remand for that purpose.