The Code of Criminal Procedure (Japan)

Introduction

The Code of Criminal Procedure (Keiji Soshō Hō, Act No. 131 of 1948, effective 1 January 1949) is Japan’s primary procedural statute for the investigation, prosecution, trial, and appeal of criminal offences. It replaced the pre-war Code of Criminal Procedure of 1922, which had been modelled on the German Strafprozessordnung. The 1948 Code was enacted during the Allied Occupation and reflects substantial American influence, particularly in the introduction of the warrant requirement, the right to counsel, the privilege against self-incrimination, and an adversarial trial structure. At the same time, the Code retains features of the continental inquisitorial tradition, including the active role of the judge in examining evidence and the extensive use of written documentary evidence.

The Code has been extensively amended. The most significant reforms include the 2004 reforms (the introduction of the saiban-in lay judge system), the 2016 reforms (the introduction of plea bargaining, the tiered disclosure system, and the audio-visual recording of interrogations), and the 2023 reforms (the revision of sexual offence procedures and the introduction of protections for vulnerable witnesses).

Structure

The Code of Criminal Procedure is divided into six parts:

• Part I — General Provisions (Articles 1–135): jurisdiction, court composition, disqualification of judges, the rights of the accused, the privileges of witnesses.
• Part II — First Instance (Articles 136–350): investigation, arrest, detention, indictment, pre-trial procedure, trial, evidence, judgment.
• Part III — Appeals (Articles 351–421): kōso (appeal to the High Court), jōkoku (appeal to the Supreme Court), kōkoku (special appeals).
• Part IV — Retrial and Extraordinary Appeals (Articles 422–447): saishin (retrial), extraordinary appeals on points of law.
• Part V — Execution of Judgments (Articles 448–475): the enforcement of sentences, including the death penalty and imprisonment.
• Part VI — Special Provisions (Articles 476–512): special procedures for certain categories of offences.

The Constitutional Framework

The Code operates within the framework of the Constitution of Japan, which guarantees fundamental rights in the criminal process:

• Article 31: no person shall be deprived of life or liberty “except according to procedure established by law.”
• Article 33: no person shall be arrested except upon a warrant issued by a judge.
• Article 35: the right against warrantless entry, search, and seizure.
• Article 36: the prohibition of torture and cruel punishments.
• Article 37: the rights of the accused, including the right to a speedy trial, the right to examine witnesses, and the right to counsel.
• Article 38: the privilege against self-incrimination and the exclusion of coerced confessions.

The Supreme Court has the power to review the constitutionality of criminal procedure under Article 81 of the Constitution, and it has exercised this power in landmark cases such as Hirano Jiken (the exclusionary rule for illegally obtained evidence) and Eniwa Jiken (the constitutionality of the Self-Defence Forces in the context of criminal procedure).

Investigation

The Code prescribes the investigation powers of the police and the public prosecutors.

Warrant Requirement. Article 218 requires a judicial warrant for the seizure of evidence, the search of premises, and the arrest of a suspect. Exceptions exist for flagrante delicto (Article 213: a private person may arrest without warrant) and for urgent circumstances (Article 210: a warrantless arrest is permissible where there is “sufficient reason to suspect” the person has committed a serious offence).

Pre-Indictment Detention. Following a warrant arrest, the suspect must be brought before a judge within 48 hours (Article 205). The judge may order detention (kōryū) for up to ten days, extendable to a maximum of 23 days (Articles 207–208). Detention is typically in police cells (daiyō kangoku), a practice that has been criticised by the United Nations Human Rights Committee.

Interrogation. The Code does not expressly require the presence of defence counsel during interrogation, and in practice counsel is not present. The 2016 reforms introduced the mandatory audio-visual recording of interrogations for offences subject to the saiban-in system. The Supreme Court has excluded confessions obtained by prolonged interrogation or coercive methods.

The Indictment Decision

The prosecutor has the exclusive power to indict (the prosecution monopoly). The prosecutor enjoys broad discretion under Article 248 CCrP to decline prosecution where “the character, age, and circumstances of the offender, the gravity of the offence, and the circumstances after the offence” make prosecution unnecessary. This discretionary non-prosecution (kiso yūyo) is used in a large proportion of cases, particularly for minor offences and first-time offenders.

The victim may challenge a non-prosecution decision by applying to the Committee for the Inquest of Prosecution (Kensatsu Shinsa Kai). Since 2009, a second committee opinion recommending indictment is binding and triggers the appointment of a prosecutor to pursue the case.

Pre-Trial Procedure

The preliminary hearing (shinsa) was introduced in the 2004 reforms. It is a conference at which the court and the parties identify the contested issues and plan the examination of evidence. The prosecutor must disclose evidence at this stage. The 2016 reforms introduced a tiered disclosure system:

• Type I evidence: evidence that forms the core of the prosecution’s case (must be disclosed early).
• Type II evidence: exculpatory evidence (must be disclosed on the defence’s specific request).
• Type III evidence: other relevant evidence (disclosed on further order of the court).

The 2016 reforms also introduced the pre-indictment discussion meeting (kōgi-mae no gōi), in which the prosecutor and the defence may discuss the charges and the possibility of a guilty plea. This is Japan’s form of plea bargaining, limited to economic crime and regulatory offences.

Trial

The criminal trial is adversarial in structure but retains inquisitorial elements.

Composition. For serious offences (murder, robbery causing death, arson, certain drug offences), the case is tried by a mixed panel of six lay judges (saiban-in) and three professional judges. For less serious offences, a single professional judge or a three-judge panel hears the case.

Opening Statements. The prosecutor opens, followed by the defence.

Examination of Evidence. The prosecution presents its evidence first. Documentary evidence is extensively used. The Code permits the admission of written statements (kensatsu chōsho and keisatsu chōsho) as evidence, provided the witness is available for cross-examination. The defence may present its own evidence. The judge has the power to examine witnesses (Article 298 CCrP) and to call evidence on the court’s own motion.

Judgment. The court must be convinced of guilt beyond a reasonable doubt (Article 317 CCrP). The judgment must state the reasons for the finding on each contested issue. The conviction rate exceeds 99%.

Sentencing. The prosecution makes a sentencing recommendation (kankoku). The defence presents mitigating evidence. Victim impact statements are permitted. The court imposes sentence within the statutory range.

Appeal

Kōso (appeal to the High Court) lies as of right against any conviction (Article 372 CCrP). The appellant may argue errors of fact and law. The High Court reviews the record and may acquit, convict of a lesser offence, or remit.

Jōkoku (appeal to the Supreme Court) is limited to constitutional error and conflict with Supreme Court precedent (Article 405 CCrP). The Supreme Court grants jōkoku in fewer than 5% of petitions.

Kōkoku is a special appeal against interlocutory orders.

Post-Conviction Remedies

Retrial (saishin) is available where new evidence casts doubt on the conviction (Articles 435–436 CCrP). The retrial procedure has been used in high-profile capital cases, including Hakamata Jiken (retrial granted in 2023, acquittal in 2024 after 47 years on death row) and the Ashikaga Jiken.

Extraordinary Appeal (hi-jō jōkoku). The Prosecutor-General may appeal to the Supreme Court against a final judgment that violates the law, even after the judgment has become final (Article 458 CCrP).

The 2004, 2016, and 2023 Reforms

The 2004 reforms were the most significant since the Code’s enactment. They introduced the saiban-in system, the preliminary hearing, and the expanded disclosure of evidence. The reforms were part of the broader Justice Reform (Shihō Seido Kaikaku) agenda, which aimed to increase public participation in the justice system, to accelerate proceedings, and to improve the quality of fact-finding.

The 2016 reforms introduced plea bargaining, the tiered disclosure system, and the recording of interrogations. These reforms were driven by concerns about wrongful convictions (particularly in the Ashikaga case) and by the need to combat corporate and economic crime more effectively.

The 2023 reforms focused on sexual offences, revising the procedural rules to protect vulnerable witnesses (including the use of screens and video links) and to ensure that victims are not subjected to inappropriate questioning about their sexual history.