What is the Purpose and Legal Basis of Interrogation in Japan?

Japanese Attorney at Law - Bengoshi L.L.

• 6 min read

Criminal interrogation, known in Japanese as torishirabe (取調べ), stands as a pivotal and often intensely scrutinized component of Japan's criminal justice system. For anyone interacting with or observing this system, understanding the objectives that drive interrogations and the legal foundations upon which they are built is crucial. This article delves into the core purposes and legal underpinnings of interrogation practices in Japan, offering a comprehensive overview for those seeking a deeper understanding.

The authority to conduct interrogations and the parameters within which they must operate are primarily derived from Japan's Constitution and, more specifically, its Code of Criminal Procedure (刑事訴訟法 - Keiji Soshō Hō, hereinafter CCP).

Constitutional Basis:
While the Constitution of Japan does not explicitly detail interrogation procedures, it lays down fundamental human rights that indirectly shape them. Article 38, for instance, guarantees the right against self-incrimination, stating that no person shall be compelled to testify against himself. This principle profoundly influences the nature and limits of permissible interrogation techniques.

The Code of Criminal Procedure (CCP): The Primary Source
The CCP provides the direct legal authority for investigators to conduct interrogations. Key articles include:

  • Article 197(1) CCP: This article serves as a general empowering provision for criminal investigations. It states that, with regard to an investigation, public prosecutors, public prosecutors' assistant officers, and judicial police officials may conduct necessary torishirabe (investigations or examinations, which in a broader sense includes interrogation) to achieve its purpose, except as otherwise provided in the CCP. This provision establishes the general power of investigative bodies to take steps required to uncover facts and gather evidence.
  • Article 198(1) CCP: This is the most direct and frequently cited legal basis for the interrogation of suspects. It stipulates that public prosecutors, public prosecutors' assistant officers, or judicial police officials may, when it is necessary for the investigation of an offense, request the appearance of a suspect and interrogate him/her. However, it also clarifies an important right: except in cases where the suspect is under arrest or detention, the suspect may refuse to appear or, after appearing, may leave at any time.
  • Article 223(1) CCP: This article extends the power of interrogation beyond suspects to other individuals who may possess information relevant to an investigation. It states that public prosecutors, public prosecutors' assistant officers, or judicial police officials may, when it is necessary for an investigation, request the appearance of a person other than the suspect (often referred to as a witness or person of interest - sankōnin 参考人) and interrogate them. This allows investigators to gather a wider range of testimonial evidence.

Defining "Torishirabe" (Interrogation)

The term torishirabe itself carries nuances depending on the context.

Narrow Definition:
In its most common and narrow sense, particularly when discussing the questioning of individuals, torishirabe refers to the act of an investigator (such as a police officer or prosecutor) posing questions to a suspect or a witness, and seeking answers or explanations from them. The primary goal here is the collection of testimonial evidence – statements that can shed light on the facts of a case. This involves a direct interaction where an investigator actively elicits information.

Broad Definition:
Article 197(1) CCP uses torishirabe in a broader sense. Here, it is interpreted to mean not just the questioning of individuals, but rather "all necessary measures and methods required for the purpose of investigation." This could encompass a wide array of investigative activities beyond direct questioning. However, for the purposes of this article, and in common legal discourse concerning interactions with suspects and witnesses, the narrow definition of active questioning to obtain statements is the primary focus.

The Purpose and Significance of Interrogation in the Japanese System

Interrogation is not merely a procedural step; it serves several critical functions within the Japanese criminal justice framework, all aimed at achieving the overarching goal of "clarifying the truth" (shinsō kaimei 真相解明).

1. Crucial Method of Evidence Collection:
Interrogation is considered a highly important, and often indispensable, method of evidence collection. While physical evidence is vital, statements obtained through interrogation frequently provide the necessary context or links to make such evidence meaningful.

  • Connecting Physical Evidence to the Crime: Even if a potential weapon is found, a suspect's statement admitting to its use and explaining the circumstances can be the key to irrefutably linking the object to the commission of the crime. For example, if a wooden stick suspected of being used in an assault is discovered, a suspect’s statement affirming its use to strike the victim clarifies the connection between the evidence and the offense.
  • Proving Subjective Elements (Mens Rea): Many criminal offenses in Japan require proof of subjective elements such as intent (koi 故意), purpose (mokuteki 目的), or conspiracy (kyōbō 共謀). These internal states of mind are often exceptionally difficult, if not impossible, to establish solely through objective or physical evidence. Interrogation of the suspect or related parties becomes paramount in uncovering these crucial aspects.
    • Intent: For example, in a homicide case, distinguishing between murder (requiring intent to kill) and manslaughter might heavily rely on the suspect’s statements about their state of mind and intentions during the incident.
    • Purpose: Certain crimes, like breach of trust for a specific illicit purpose, require proving that purpose, often only ascertainable through statements.
    • Conspiracy: Establishing a criminal conspiracy often necessitates statements from co-conspirators detailing their agreements and shared criminal designs. Crimes such as bribery, complex financial fraud, or violations of election laws frequently depend heavily on the testimony of those involved to bring the full picture of the offense to light.

2. Clarifying the Truth and Exonerating the Innocent:
A fundamental objective of the Japanese criminal justice system, as enshrined in Article 1 of the CCP, is the pursuit of "substantive truth" (jittaiteki shinjitsu shugi 実体的真実主義). Interrogation plays a vital role in this pursuit.

  • Investigator's Duty: Investigators have a duty to explore all facets of a case, including those that might point away from the suspect's guilt.
  • Hearing the Suspect's Account: When a suspect denies involvement or offers an alternative explanation (such as an alibi), interrogation provides the forum for investigators to hear this account in detail. It is then incumbent upon the investigators to thoroughly examine such claims. For instance, if an alibi is asserted, its details must be carefully elicited through interrogation, followed by verification through other investigative means. The interrogation process itself allows for a detailed examination and critical assessment of the suspect's statements.
  • Prompt Exoneration: If a suspect is indeed innocent, their statements, when properly investigated and verified, can lead to their swift exoneration, preventing wrongful prosecution and detention. This aspect underscores the dual role of interrogation: not only to secure evidence against the guilty but also to protect the innocent.

The Nature of Suspect Interrogation: Inquisitorial and Accusatorial Influences

The fundamental nature of suspect interrogation in Japan is a subject of ongoing legal discussion, often framed by contrasting the inquisitorial and accusatorial models of criminal procedure.

  • Accusatorial Model: Typically associated with Anglo-American legal systems (like that of the United States), this model views the trial as a contest between two opposing parties (prosecution and defense) before a neutral judge. In its purest form applied to investigations, it would suggest that the suspect, as a party, should not be subjected to extensive interrogation by the opposing side (the investigators). The focus would be primarily on gathering external evidence.
  • Inquisitorial Model: Traditionally associated with Continental European legal systems, this model places a greater emphasis on the role of an impartial investigating magistrate or official whose duty is to uncover the truth, often through extensive examination of the suspect and witnesses. The investigation is seen less as a prelude to an adversarial contest and more as an active inquiry to establish facts.

While Japan's trial procedures are largely adversarial and based on the accusatorial model (especially after post-WWII reforms), its investigative phase, particularly concerning suspect interrogation, retains strong characteristics that can be described as inquisitorial, or, as some Japanese scholars prefer, "justice-realizing" (seigi jitsugen-gata 正義実現型).

The rationale often provided is that the CCP’s primary objective of achieving "substantive truth" necessitates a proactive investigative approach where the suspect’s own account and admissions are considered vital. It is argued that for many types of crimes—especially sophisticated white-collar offenses, organized crime involving intricate conspiracies, or crimes where direct physical evidence is scarce or has been destroyed—it is exceedingly difficult to ascertain the full truth without the statements of those directly involved, including the suspect. Furthermore, understanding the motive behind a crime, a crucial element in many cases, often relies almost exclusively on what the suspect reveals.

Even proponents of a more active investigative role acknowledge the inherent risks, such as the potential for coerced confessions, which is why safeguards like the right to remain silent and rules on the admissibility of confessions are in place. Nevertheless, the prevailing ethos in Japanese investigative practice often emphasizes the investigator's responsibility to actively seek out all information, including that which can be obtained from the suspect, to paint a complete picture of the events in question. It's seen not merely as building a case against a suspect, but as a comprehensive effort to understand what truly transpired.

This perspective views the investigator not just as a party preparing for an adversarial contest, but as an agent tasked with a thorough and, if necessary, probing inquiry to fulfill the system's commitment to substantive truth.

Conclusion

Interrogation in Japan is a legally sanctioned and central component of the criminal investigation process. Grounded in the Code of Criminal Procedure, its primary purposes are the comprehensive collection of evidence—especially for subjective elements of crimes that are otherwise difficult to prove—and the overarching aim of clarifying the substantive truth of a case, which includes the exoneration of the innocent. While operating within a system that has adopted adversarial trial structures, the investigative phase, and interrogation within it, often reflects a more inquisitorial or "justice-realizing" approach, underscoring the investigator’s active role in uncovering all relevant facts. Understanding this legal basis and multifaceted purpose is essential for comprehending the dynamics of criminal justice in Japan.