In brief

The investigation is where the most important decision of the whole criminal case is made: charges or dismissal. Whatever is not in the file by then will be missing in court later.

As soon as the public prosecutor learns of a suspected offence, the facts must be investigated (Section 160(1) StPO). The prosecutor directs the proceedings and the police investigate on its behalf (Sections 161 and 163 StPO). Under Section 160(2) StPO, exonerating circumstances must be investigated as well as incriminating ones. That duty is in the statute. In practice whether it is fulfilled depends heavily on whether anyone points those circumstances out.

The investigation ends with a final decision. If the file provides sufficient grounds, the prosecutor files an indictment or applies for a penalty order. Otherwise the case is discontinued, either for lack of sufficient suspicion under Section 170(2) StPO or on discretionary grounds under Sections 153 et seq. StPO. The prosecution statistics of the Federal Statistical Office show year after year that discontinuation is the most common outcome.

How people find out

There is no notification that an investigation has been opened. Many cases run for months without the person concerned suspecting anything. Usually it becomes apparent through a summons, a written questionnaire, a search or a call from an officer who “just wants to clarify something”. Some only learn of it from a penalty order.

How long it takes depends on the allegation and on the authorities’ workload. Simple cases are dealt with in three to six months. Commercial and benefit fraud cases involving data analysis not infrequently take one to two years.

Why the defence achieves most at this stage

Before the final decision, the case can still be ended without a public hearing. We obtain access to the file, check whether the suspicion holds, suggest evidence the police overlooked and talk to the prosecutor about a dismissal. A well-reasoned submission at this point often avoids a main hearing, and with it an entry in the register.

General explanation, not advice on an individual case. As of November 2026.