Investigative questions in criminal law: Articles 348 and 350 Sv explained

The investigative questions are the fixed set of questions a Dutch criminal court must answer, in a set order, before it convicts or acquits. Four formal questions follow from Article 348 of the Code of Criminal Procedure (Wetboek van Strafvordering, Sv) and four substantive questions from Article 350 Sv; if a formal question is answered against the prosecution, the case ends there and the court never weighs the evidence.

The order decides where a defence argument must be made, what the court must respond to in its judgment and which investigative requests (onderzoekswensen) are worth making. This article explains both sets of questions and how the suspect, the Public Prosecution Service (Openbaar Ministerie, OM) and the victim can influence the answers.

What are the four formal questions of Article 348 Sv?

Before the merits, the court checks whether the case has been validly brought. It answers four questions in this order.

1. Is the summons valid? The charge, time and place must be clear enough for you to prepare a defence; if not, the summons is declared void.
2. Does the court have jurisdiction over the offence charged?
3. Is the OM admissible? This is where limitation, prosecution in breach of the principles of proper procedure or an earlier decision not to prosecute are raised.
4. Are there grounds to suspend the prosecution, for example because the suspect is not fit to stand trial?

A negative answer ends the case without a ruling on guilt. These are the only points on which a case can be stopped before the evidence is weighed, so they deserve full attention in the defence.

What are the four substantive questions of Article 350 Sv?

Once the formal questions are cleared, the court decides the merits by answering four further questions in order.

1. Is it proven that the suspect committed the act charged? Under Articles 338 and 339 Sv this requires legal means of evidence and the court’s own conviction.
2. Is the proven act a criminal offence (qualification)?
3. Is the suspect criminally liable? Here the court assesses grounds of justification, such as self-defence (noodweer), and grounds of excuse, such as psychological force (psychische overmacht).
4. Which sentence or measure should be imposed?

The difference between the second and third questions often decides a case. A ground of justification means the act was not unlawful; a ground of excuse means the act was unlawful but the suspect cannot be blamed. Both lead to discharge from prosecution (ontslag van alle rechtsvervolging), not an acquittal, but they rest on different facts and evidence.

Why does the order of the questions matter?

The court must answer the questions in sequence and give reasons. If the defence has put forward a reasoned argument on one of the questions, the judgment must deal with it; a judgment that passes over such an argument can be challenged on appeal and in cassation.

The new Code of Criminal Procedure has been adopted, with entry into force planned for 2029. Until it enters into force, Articles 348 and 350 Sv remain the provisions to cite. The reform keeps the model of formal questions before substantive ones.

How can the defence steer the investigation?

The file is compiled by the police under the direction of the OM. A defence that waits for the hearing to test it is usually late, because by then witnesses have been heard once and forensic material examined once. The better route is to identify which question of Article 348 or 350 Sv is contestable and request the investigation that could change the answer.

• Before trial: under Article 182 Sv you can ask the examining magistrate (rechter-commissaris) to carry out investigative acts, such as hearing witnesses or appointing an expert.
• Expert findings: Articles 150a and 150b Sv govern notice of expert findings and requests for a further or counter-investigation.
• Before the hearing: under Article 263 Sv you can ask the public prosecutor to summon witnesses and experts, at the latest ten days before the hearing.
• At the hearing: further investigation can be requested from the trial court (Article 328 Sv); on appeal, new witnesses and experts can be requested (Article 414 Sv).

What makes a request succeed is its reasoning. In its judgment of 18 November 2025 (ECLI:NL:HR:2025:1711) the Supreme Court (Hoge Raad) held that the defence must state which parts of an incriminating expert report it disputes and why hearing the expert is preferable to another form of testing. The court must also check that the trial as a whole stays fair if it refuses.

A request is not automatically granted. In a traffic case under Articles 5 and 6 of the Road Traffic Act 1994 (Wegenverkeerswet 1994), the District Court of Rotterdam on 14 August 2019 (ECLI:NL:RBROT:2019:7166) upheld the examining magistrate’s refusal to appoint an independent expert on the suspect’s visibility, because the file already contained enough information. The court noted that the defence could still instruct its own expert at its own cost.

When can a request be refused?

The public prosecutor may refuse to summon a witness requested under Article 263 Sv on limited grounds, for example where it can reasonably be assumed that the defence is not harmed by the refusal. A refusal must be given in writing with reasons, and you can renew the request before the trial court.

In the pre-trial phase, a refusal by the examining magistrate can be put before the court (Article 182 Sv), as in the Rotterdam case above. The test is whether the investigation is necessary or reasonably relevant to one of the questions the court must answer, and whether refusing it would leave you without a fair trial. That is why a request framed in terms of Article 348 or 350 Sv works better than one framed around what the defence would like to know.

What is the role of the Public Prosecution Service?

The OM directs the investigation: it decides which leads the police follow, can ask the examining magistrate for investigative acts (Article 181 Sv) and summons the witnesses and experts it considers necessary. That gives it the first say on the content of the file.

The prosecutor must also establish the truth, which includes securing material that points away from the suspect. A file that contains only what supports the charge is itself a reason for a request. Where the OM and the defence disagree, the examining magistrate decides before trial and the trial court afterwards.

What rights does the victim have?

The victim is a participant with defined rights, not a party like the defence and the OM. Under Article 51b Sv the victim can ask the public prosecutor to add documents relevant to the victim to the file and to receive copies; a refusal must be in writing, and the victim can then turn to the examining magistrate.

The right to speak (spreekrecht) under Article 51e Sv concerns the impact of the offence, not the evidence. If a victim states facts at the hearing that do not match the file, the court may order further investigation of its own motion, but the victim cannot compel an investigative step the way the defence can. Our article on the criminal court hearing in the Netherlands explains how the hearing is structured.

What should you check as a suspect?

• Whether the charge states the act, time and place clearly enough (validity of the summons, Article 348 Sv).
• Whether limitation or an earlier decision not to prosecute may make the OM inadmissible.
• Which of the four questions of Article 350 Sv is genuinely contestable on the file as it stands.
• Which witnesses or experts could change that answer, and whether the request can still go to the examining magistrate (Article 182 Sv).
• Whether witnesses and experts for the hearing have been requested at least ten days before it (Article 263 Sv).

What should you check as a victim?

• Whether documents relevant to you are in the file, and if not, whether to ask the prosecutor to add them (Article 51b Sv).
• Whether you want to use your right to speak at the hearing (Article 51e Sv) and what you want to say about the impact.
• Whether you have joined the proceedings as an injured party for your claim, and with which supporting documents.
• Whether facts you know are missing from the file and should be raised with the prosecutor in good time.

When should you act?

Timing is the part most often underestimated. In the pre-trial phase, before the examining magistrate, witnesses can still be heard properly and counter-expertise can be arranged without delaying the trial; once the case is listed, the threshold for the same request rises.

Advice at the first police interview, before positions are recorded, is usually worth more than advice a month before the hearing. Our article on when you need a criminal defence lawyer sets out that timing in more detail.

What can we do for you with investigative requests?

Our lawyers in criminal law act for suspects and victims, in Dutch and in English.

• We assess the case file against the formal questions of Article 348 Sv and the substantive questions of Article 350 Sv.
• We draft reasoned investigative requests to the examining magistrate (Article 182 Sv) and the public prosecutor (Article 263 Sv).
• We request a counter-investigation of expert findings and propose a suitable expert.
• We challenge refusals before the examining magistrate and the trial court.
• We assist victims in adding documents to the file (Article 51b Sv) and preparing their statement at the hearing.

Summary

• A Dutch criminal court first answers four formal questions (Article 348 Sv), then four substantive questions (Article 350 Sv).
• A negative answer to a formal question ends the case without a ruling on guilt.
• Justification and excuse lead to discharge from prosecution, not acquittal.
• Investigative requests succeed when they are linked to a specific question and well reasoned (ECLI:NL:HR:2025:1711).
• Victims can ask for documents to be added (Article 51b Sv) but cannot force investigative steps.

Frequently asked questions