Police Investigation Procedure

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Select your current step and the content for that step will appear below.

1. 1Receiving the Request to Appear
2. 2Preparing for Questioning
3. 3Suspect Interrogation
4. 4Reading and Correcting the Record
5. 5Search and Seizure, Confrontation and Forensics
6. 6Submitting a Written Opinion and Settlement Materials
7. 7Referral / Non-referral Decision

• Basic step
• Additional action / option
• Rejection / objection
• End of procedure

Time required

For criminal complaint and accusation cases, the police must finish the investigation and decide whether to refer the case within 3 months from the day they accepted it. This applies to cases accepted on or after 2026.10.2

Cost

The law does not set any separate fee for being questioned by the police. Hiring a defense lawyer costs a retainer fee

Procedure guide

Read from start to finish in order. Red text marks deadlines set by law.

1. 1

   The police make a request to appear (a notice telling you to come in for questioning) by phone, text message or mail. At this point, ask and confirm the case number, the charge, the investigator in charge and whether it is a criminal complaint case. You can change the date of appearance by arranging it with the investigator. However, if you do not respond to a request to appear without a good reason, an arrest warrant may be requested (Criminal Procedure Act §200-2(1)), so even if you change the date, be sure to appear.

2. 2

   Before appearing, organize what happened in time order and gather materials in your favor, such as text messages, recordings and bank account records. If the order is organized, your statements will not conflict even when you are questioned. With your defense lawyer, separate what you admit from what you contest, and decide in advance how you will make your statement. This way you can avoid saying unnecessary things in questioning.

3. 3

   On the day of questioning, the investigator carries out the suspect interrogation (the police ask questions and the suspect answers). Before questioning starts, you are told about the right to remain silent (the right not to speak) and the right to the assistance of counsel (the right to get help from a defense lawyer). The defense lawyer can take part in the questioning and state opinions (Criminal Procedure Act §243-2). For things you do not remember clearly, answer 'I don't know' or 'I don't remember'. This is because answers based on guesses also stay in the record as they are.

4. 4

   When the interrogation ends, read the suspect interrogation record (the document recording the questioning) from start to finish. If any part is written differently from your statement, ask for it to be corrected or added to, and then sign and seal it (§244). This record is used as evidence at trial if the defendant admits its content (§312(3)), so check it carefully line by line.

5. 5

   If needed, the police obtain a warrant from a judge and carry out search and seizure (§215), or carry out digital forensics on phones and computers (restoring and analyzing stored data). If you delete materials after receiving a request to appear, this may be seen as a risk of destroying evidence and become a ground for detention (§70(1) item 2). If your statement conflicts with the complainant's, confrontation questioning (questioning both sides sitting together) is carried out. Questioning may not end in one session; there may be more.

6. 6

   Before the case is sent to the prosecutor (referral), submit the defense lawyer's written opinion, materials on restoring damage and settlement, and evidence in your favor to the investigator. Before ending the investigation, the police check whether you intend to submit materials or opinions, and file the submitted materials in the investigation record (Investigation Rules §25(2)). A settlement with the victim is carried out through your defense lawyer.

7. 7

   If the police find the charges are supported, they send the case to a prosecutor of the Public Prosecution Office (formerly the Prosecutors' Office) (referral, §245-5); if not, they close the case with a non-referral decision. In the case of non-referral, the complainant is told the reasons within 7 days (§245-6), and the suspect is also notified of the investigation result. If the complainant files an objection, the case goes to the prosecutor, so the procedure can continue even after non-referral.

   Current step

Frequently asked questions

Practical questions that come up right away in this procedure.

QDo I have to go on the date written on the request to appear?

It does not have to be that exact date. You can call the investigator in charge and adjust the date. If a suspect asks to postpone the date and time of appearance, the police must adjust it unless there are special circumstances.If you have a defense lawyer, the schedule is also arranged with the lawyer. However, if you do not respond to a request to appear without a good reason, an arrest warrant may be requested.

QWhat should I bring when I am questioned?

Bring your ID, the request to appear, and copies of materials in your favor (screenshots of messages, recording files, bank account records). Also bring a memo setting out the facts in time order. Keep the original phone or documents yourself until you are asked to submit them.This is because bringing only copies lets you keep the originals intact. If the suspect's statement is to be video-recorded, you must be told in advance.

QHow many hours does questioning take, and how many times will I be questioned?

It depends on the case. The total questioning time, including waiting, breaks and meals, cannot exceed 12 hours. The actual questioning time cannot exceed 8 hours unless there are special circumstances.You cannot be questioned again until 8 hours have passed after the questioning ends. Late-night questioning from 9 p.m. to 6 a.m. is not allowed in principle.It is allowed only in exceptional cases, such as when you request it yourself giving specific reasons. The number of questioning sessions also depends on the case.

QCan I go alone without a lawyer?

You can be questioned even if you go alone. However, in cases where your statement conflicts with the complainant's, where you contest the charges, or where you may be detained, a defense lawyer should take part and help set the direction of your statements.This is because what you say in questioning is written in a record of statement and stays in the case file. During questioning, the defense lawyer can state opinions and object to improper questions.

QHow do I know whether I am a suspect or a witness?

Ask the investigator in charge in what capacity you are being called and what the charge is. The request to appear must state the purpose of the request, such as the summary of the alleged facts (a summary of the charges). When interrogating a suspect, the police must tell you about the right to remain silent (the right not to speak) before starting.

QCan I get a copy of what was recorded in my questioning (the record of statement)?

Yes, you can apply. In a case under investigation, you can apply to inspect and copy the parts containing your own statements and the documents you submitted.The police must allow it unless there is a good reason, such as a risk of infringing personal information or of destroying evidence. Check with the investigator in charge how to apply and how much it costs.