The First 72 Hours After Arrest in a Drug Case: What Happens Before Detention Is Decided

Your family member was taken away by the police over a suspected drug offence, you cannot reach them, and the hours are going by. This page is written for you. Nothing appears to be moving from the outside, but the procedure moves quickly, and only about 72 hours pass before it is decided whether the person will be held in detention. What is said and what is assembled in that window will shape the eventual disposition, and with it the future of the person's status of residence (在留資格). Simply knowing what is going on makes it easier to think clearly.

Key points

• After arrest, the case and the person are referred by the police to the prosecutor, the prosecutor requests detention, and a judge conducts detention questioning. The whole sequence fits within roughly 72 hours.
• The statement recorded at the outset and the written statements taken during this period become the foundation for the later decision on disposition.
• In a case involving a foreign national, the quality of interpretation and the handling of consular notification should be checked at an early stage.
• In a drug case the conviction itself is a ground for deportation (退去強制) under Article 24, item 4, sub-item (chi) (入管法24条4号チ), so the strategy has to account for residence from the very first steps.
• The duty attorney (当番弁護士) system provides a single visit; continuous representation begins only once defence counsel is separately appointed.

How do the first 72 hours actually unfold?

Start with the skeleton of the procedure. A person who has been arrested is held in a detention facility at a police station, and within a limited period the police refer the case and the person to the prosecutor. The prosecutor, again within a limited period, requests detention from a judge if satisfied that continued custody is necessary. The judge then meets the person, conducts detention questioning, and rules on the request. That is the sequence covered by roughly 72 hours from arrest.

If detention is granted, custody continues for ten days as a rule, and for up to a further ten days if an extension is allowed. The prosecutor must decide whether to bring charges by the time that period ends.

Why do these three days shape the whole case?

Because what is said at the outset is referred back to again and again as the process continues. A statement is recorded immediately after arrest, and questioning continues from there. At that stage the person is answering questions without a full grasp of Japanese procedure, tired and anxious. What they say is fixed in writing, and if they later explain matters differently they will be asked why their first account was different. That is what gives the earliest response its weight.

In drug cases in particular, how the person described their awareness of the substance, who they said they received it from, and when and where they said they used it feed directly into the issues that arise later. Correcting a written statement once it has been made and does not match the facts is not easy. That is why arranging the first detention visit as early as possible, explaining the procedure and settling the approach matters so much.

How does a duty attorney differ from privately retained counsel?

The duty attorney system is one under which, at the request of a person who has been arrested, the bar association dispatches a lawyer once. It is valuable for the advice you receive on the spot, but as a rule it is a single visit, and continuous work begins only when defence counsel is separately appointed. At this point the choice arises between retaining private counsel and, if the means requirement is satisfied, requesting court-appointed counsel.

A foreign national's drug case calls for an arrangement in which the likely criminal disposition and the effect on residence can be considered together. Set a strategy by looking only at the criminal process and you risk failing to factor in what a conviction does to residence. When choosing counsel, please do not hesitate to ask whether the consequences under the immigration statute will be explained to you as well.

Interpretation and consular notification: points to check

Interpretation used in the investigative process is arranged by the investigating authorities. Disputes about an interpreter's competence and neutrality do occur in practice, and a carefully hedged phrase can end up recorded as a flat assertion. We make a point of telling clients early that they may ask about any word they do not understand, and that they are not required to sign something they do not follow.

Article 36(1)(b) of the Vienna Convention on Consular Relations provides, among other things, that where a foreign national in custody so requests, the consular post of their home country is to be notified without delay. Whether the consular post is contacted therefore depends on the person's own wishes. Where the family cannot be reached, that notification is sometimes the first line of connection.

What family members can put in place now

It can feel as though there is little to be done, but that is not so. Material concerning someone to take responsibility for the person and their day-to-day support in particular becomes relevant to the decision on detention and later to the disposition.

There are also things best avoided: contacting others connected with the case to align accounts, posting details on social media, and giving inaccurate explanations to an employer or school. Each can resurface to the person's disadvantage. If you are unsure, the safe course is to consult defence counsel before acting.

• Confirm which police station's detention facility the person is being held in
• Locate the person's residence card and passport, and check their status of residence and its expiry date
• Map out relationships with family living with them, the employer and the school, and consider who can take responsibility for them
• Ask the detention facility whether items may be delivered, and how
• Tell defence counsel about any chronic illness or medication

Thinking about residence from the very first steps

In a drug case, the consequences for residence must be built into the strategy from the outset. Article 24(4)(chi) makes deportable a person convicted of violating the Narcotics and Psychotropics Control Act, the Act on Regulation of Cultivation of Cannabis Plants, the Opium Act, the Stimulants Control Act, the Narcotics Special Provisions Act, or Part II, Chapter 14 of the Penal Code. It says nothing about the type or the length of the sentence, so a fine or a suspended sentence is enough.

A strategy that treats a suspended sentence at trial as the final objective has therefore set its objective in the wrong place, so far as residence is concerned. We design the matter in three tiers from the beginning: a non-prosecution decision (不起訴処分) before charges as the first line of defence, contesting the deportation process as the second, and special permission to stay (在留特別許可) as the third. What is said and what is left on the record in the first 72 hours becomes the foundation of all three.

How our office works, and matters we have handled

At Funado International Law Office, attorney Daisuke Matsumura handles every stage personally, from the first detention visit through to the close of trial. For Chinese, a dedicated interpreter experienced in cases involving foreign nationals is on staff, so that alongside the interpreter appointed by the investigating authorities you have an interpreter working for you throughout the criminal process. For languages other than Chinese, we arrange an interpreter to suit the case. Residence procedures after the criminal process are handled together with an affiliated administrative scrivener.

In a matter where a client was treated as a collector in a specialised fraud case and re-arrested several times, careful handling of the interrogations and formal objections to improper questioning produced non-prosecution decisions on every count. We have also acted for a person who had lost their status of residence and was arrested and prosecuted, negotiating with the authorities towards establishing the marriage and the acknowledgment of the child and obtaining special permission to stay on a single application through analysis of past grants, and we have experience of international criminal matters and of cases tried before lay judge panels.

The hours when you cannot reach someone feel very long. But these 72 hours are not time lost; they are the point from which everything is built. Understand the order of the procedure, settle on a strategy early, and a way forward opens up. Please note that this article is general commentary only; for your own situation, speak to a lawyer directly. Past matters turned on their own particular facts, and they are not a guarantee of a similar outcome.

This article reflects the law as at August 2026.

About the author

Daisuke Matsumura, Attorney at Law
Dai-Ichi Tokyo Bar Association (registration no. 59077, admitted 2019)
Funado International Law Office (Fuse Building Main Wing 3F, 3-4-10 Takada, Toshima-ku, Tokyo)
Practice focused on criminal defence for foreign nationals and immigration proceedings.
Results include an acquittal in a Stimulants Control Act case (possession for the purpose of profit), non-prosecution in organised fraud cases, and special permission to stay in cases regarded as difficult.

Funado International Law Office
Website: https://matsumura-lawoffice.jp/
WeChat ID: matsumura1119