When the Investigators Themselves are Questioned in Japan: How to Address Challenges to Procedural Legality (e.g., Urine Sample Collection) or Prior Interrogation Conduct?

Japanese Attorney at Law - Bengoshi L.L.

• 9 min read

In the intricate process of criminal justice, the actions and procedures employed by investigating officers are foundational to the integrity of any case. Typically, investigators are the ones asking the questions. However, there are critical junctures—particularly when a suspect or defendant challenges the legality of how evidence was obtained or the nature of prior police interrogations—where the investigators themselves become the interviewees. This shift in roles requires a careful and methodical approach to questioning, often by prosecutors or internal affairs units, to ascertain the facts and ensure accountability.

This article explores how such inquiries into the conduct of police officers are handled in Japan, focusing on two common scenarios: challenges to the procedural legality of evidence collection (using urine sample collection in a drug case as an example) and disputes over the conduct and recording of prior police interrogations.

Why Investigators May Find Themselves Under Scrutiny

The need to formally question investigating police officers typically arises in several situations:

  1. Challenges to Procedural Legality: A cornerstone of defense strategy, especially in drug offenses or cases involving searches and seizures, is to scrutinize the legality of how evidence was collected. If defense counsel alleges that evidence was obtained through an unlawful search, coerced consent, irregularities in sample handling (like a urine test), or improper execution of a warrant, the officers involved must provide a detailed factual account of their actions.
  2. Disputes Over Prior Interrogation Conduct: In Japan, while the audio-visual recording of interrogations is expanding, not all police interrogations are recorded. If a suspect makes a confession or key admissions during an unrecorded police interrogation and later recants that statement or claims it was involuntary or inaccurately transcribed into the written record (chosho, 調書) when questioned by a prosecutor (whose interrogations are more likely to be recorded for serious cases), the police officer who conducted the initial interrogation may need to be interviewed to clarify the circumstances.
  3. Clarifying Ambiguities or Gaps in Documentation: Sometimes, official police reports or statements may lack sufficient detail on a particular point, requiring follow-up questioning to ensure a complete understanding of events.

The purpose of questioning officers in these contexts is to create a clear, factual record of their actions, perceptions, and the basis for their decisions, which can then be assessed against legal standards and the suspect's allegations.

General Principles for Questioning Police Officers

When police officers are questioned about their official conduct, certain principles guide the inquiry:

  • Objectivity and Neutrality: The questioner (e.g., a prosecutor, or another police officer in an internal review) must strive for an objective and neutral stance, even though the interviewee is a fellow law enforcement professional. The aim is to elicit facts, not to prematurely defend or condemn the actions.
  • The Officer as a Key Factual Witness: The officer is a primary witness to their own actions, the procedures they followed, their interactions with the suspect, and the surrounding circumstances. Their memory, perceptions, and the rationale behind their operational decisions are all important.
  • Separate Interviews for Multiple Officers: If several officers were involved in a contested procedure (e.g., an arrest, a search, or a complex evidence collection process), they should generally be interviewed separately. This allows for their individual recollections to be obtained independently and subsequently cross-verified for consistency and completeness. The officer with primary responsibility for the specific action under scrutiny is often interviewed first to establish a baseline account.
  • Emphasis on Factual Recounting: The primary goal is to have the officer provide a detailed, chronological, and factual narrative of what occurred. While the officer's understanding of policy or their justifications for actions can be explored, this should ideally follow the establishment of the core factual sequence.

Scenario 1: Addressing Challenges to Procedural Legality – The Urine Sample Collection

Drug cases frequently involve challenges to the collection of urine samples used for drug testing. Let's consider a scenario where a suspect alleges irregularities during a compulsory urine sample collection conducted pursuant to a warrant. The suspect claims, for instance, that the officer improperly handled the collection cup mid-urination, that the suspect's view of the cup was obstructed (creating an opportunity for tampering), and that they later observed an unusual substance in the collected urine.

Investigative Questioning Strategy (Prosecutor questioning the Police Officer):

  1. Identify and Prioritize Key Officer(s): The questioning would typically begin with the officer who had the most direct responsibility for, and oversight of, the urine collection procedure – for example, the officer who explained the warrant, handed the suspect the collection kit, and supervised the actual provision and sealing of the sample.
  2. Initial Open-Ended Narrative:
    Investigator: "Officer [Name], I'd like you to describe, in detail and in chronological order, the entire procedure you followed for collecting the urine sample from Mr. [Suspect's Name] at [Location] on [Date]. Please start from when you first approached him with the warrant and continue through to when the sample was sealed and secured."
    This allows the officer to provide their uninterrupted account, which can then be probed for more specific details.
  3. Detailed Probing of Each Procedural Step:
    Based on the officer's narrative and established standard operating procedures for such collections, the questioner would seek clarification on key phases:
    • "You mentioned you instructed Mr. [Suspect] to wash the collection cup and container with water beforehand. What is the purpose of this step?" (Officer might explain it's to ensure no contaminants and to allow the suspect to verify the cleanliness, thus pre-empting certain claims).
    • "Where were you positioned while Mr. [Suspect] was actually urinating into the cup?"
    • "Who physically handled the cup containing the urine after Mr. [Suspect] had finished and before it was transferred to the sealed container?"
  4. Addressing the Specific Allegations (Methodically):
    The questioner would then address the suspect's specific claims, often by first asking open-endedly about the relevant phase, and then, if necessary, by directly presenting the suspect's allegation for the officer's response.
    • Regarding alleged interference mid-urination: "During the time Mr. [Suspect] was in the act of urinating into the cup, was the cup at any point moved, touched, or taken from him by any officer before he had completed urinating and placed the cup down himself as instructed?"
    • Regarding obstructed view/tampering: "From the moment Mr. [Suspect] provided the urine into the cup, until that urine was transferred to the final evidentiary container and that container was sealed, was Mr. [Suspect]'s direct line of sight to his urine sample ever broken or obstructed? What specific measures, if any, are typically taken or were taken in this instance to ensure the suspect has continuous observation of their sample?" (The officer might explain, for example, that standard procedure is to always keep the sample in the suspect's clear view and to have the suspect observe each step of transference and sealing precisely to prevent such allegations. Documenting this routine practice and the officer's adherence to it is crucial).
    • Regarding the alleged foreign substance: "Mr. [Suspect] has stated that after he provided the sample, and possibly after his view was briefly obstructed, he noticed a white powder-like substance floating in the urine within the cup. Did you or any other officer present observe any unusual substance, such as a white powder, in the urine sample provided by Mr. [Suspect] at any stage?" (In some training examples, officers note observing benign biological material, like protein strands, and point this out to the suspect at the time, who raises no objection. This contemporaneous interaction would be important to document).
    • If the officer denies the suspect's version: "So, to be clear, your testimony is that [reiterate the officer's factual denial of the specific allegation]?"
  5. Officer's Rationale for Adherence to Procedure:
    Investigator: "You've described the importance of the suspect maintaining an uninterrupted view of the sample. Could you elaborate on why this is a critical part of the procedure from your perspective as an investigating officer?" (The officer’s explanation, e.g., "It is to ensure transparency and to prevent any subsequent, unfounded claims from the suspect that the sample was tampered with or switched by police," demonstrates their professional understanding and intent to follow due process).

The objective is to obtain a clear, detailed, and credible factual account from the officer(s) that directly addresses each component of the suspect's procedural challenge, ideally supported by the officer's understanding of and adherence to correct procedures.

Scenario 2: Scrutinizing Prior (Unrecorded) Interrogation Conduct – The Recanted Confession

Another common situation involves a suspect who allegedly confessed during an earlier, unrecorded police interrogation but then, when formally questioned by a prosecutor (often in a recorded session), recants that confession, claims it was coerced, or states they have no memory of the event or the confession.

Investigative Questioning Strategy (Prosecutor questioning the original Police Interrogator):

  1. Establishing Context of the Initial Police Interrogation:
    Investigator: "Officer [Name], official records indicate you were the primary officer responsible for interrogating Mr. [Suspect's Name] following his arrest for [offense] on [date]. Is that correct?"
  2. Suspect's Demeanor and Statements in Early Police Handling:
    • "Can you describe Mr. [Suspect]'s demeanor and what he stated about the allegations when you first had contact with him, for example, during the initial statement recording procedures (benkai roku-shu)?" (In some examples, suspects might initially be uncooperative or claim memory loss even for basic personal details, which can be relevant context if they later confessed).
  3. Circumstances Leading to and During the Alleged Confession:
    • "The police investigation file indicates that Mr. [Suspect] subsequently confessed to the offense on [date/time of police interrogation]. Could you describe the circumstances that led to him making this confession?"
    • "What was his demeanor at the time he confessed? Was it voluntary? What specific details of the crime did he admit to?"
  4. Recording of the Police Confession (The Chosho):
    In Japanese practice, even if the interrogation itself wasn't audio-visually recorded by the police, a written summary (chosho) of the suspect's statements would have been created.
    • "The chosho documenting Mr. [Suspect]'s confession from that day is written in a question-and-answer format. Was there a particular reason you chose this format for recording his statement?" (An officer might explain, as in some training discussions, that given an initial denial or claim of memory loss, a Q&A format was used to precisely document each question asked and the suspect's specific answer, thereby aiming to ensure clarity about what was being admitted and to bolster the perceived voluntariness and credibility of the confession).
    • Addressing "Memory Lapses" Within the Confession: "The chosho also notes that when you asked Mr. [Suspect] about [specific detail X, e.g., why he purchased an unrelated item during a shoplifting spree], he responded, 'I don't remember.' Similarly, when asked [specific detail Y], he again stated, 'I don't remember.' Do these entries in the chosho accurately reflect his responses to those particular questions, even as he was admitting to the main offense?" (If the officer confirms this, it demonstrates their diligence in accurately recording the entirety of the suspect's statement, including parts that were not inculpatory or showed memory gaps, which can enhance the officer's credibility and the overall reliability of the chosho).
  5. Voluntariness of the Police Confession:
    • "During your interrogation of Mr. [Suspect] that led to this confession, were any promises of leniency, threats, physical force, or other forms of improper inducement used?"
  6. Officer's Perspective on the Suspect's Later Recantation/Memory Loss:
    Investigator: "Mr. [Suspect] has now stated during my interrogation, which was audio-visually recorded, that he has no memory of committing the [offense] or of confessing to you. Having taken his detailed confession previously, what is your professional view on his current assertion?" (The officer might state, for example, that given the level of specific detail the suspect provided during the police confession, a complete loss of memory now seems improbable).

Broader Implications for Statement Discrepancies

The need to question officers about prior statements is not limited to suspect recantations. If any witness, including a victim or a third-party reference person, provides an account to the prosecutor that significantly differs from what they reportedly told the police (documented in a police-generated chosho), the prosecutor must address this discrepancy. This often involves:

  1. Asking the witness if they recall their prior statement to the police.
  2. Showing them the relevant part of their police-generated chosho (if available and appropriate).
  3. Asking them to confirm if that chosho accurately reflected what they said to the police at that time.
  4. Asking them to explain which version is correct and, critically, why their account has changed or now differs.

This principle of diligently addressing and documenting the reasons for any significant testimonial discrepancies applies equally when the "witness" being questioned about a prior account is an investigating officer discussing their own reports or actions.

The Impact of "Visualization" and Documentation

The increasing use of audio-visual recording in prosecutor-led interrogations (and for certain police interrogations) adds a significant dimension. Even if the original police interaction or interrogation under scrutiny was not recorded, the prosecutor’s subsequent interview with the police officer about those past events can be, and often is, recorded. This creates a new, verifiable record of the officer's account of their own prior conduct. It encourages precision and accountability from the interviewed officer. Furthermore, an officer's own contemporaneous notes, formal investigation reports (sōsa hōkokusho), and the chosho they drafted become crucial documents that they may be asked to review and affirm during such questioning.

Conclusion: Upholding Procedural Integrity Through Inquiry

Questioning investigating police officers about their own conduct or the procedures they employed is a specialized but indispensable task within the Japanese criminal justice system, particularly when challenges to evidence or prior statements arise. It is not an adversarial process by default, but rather a methodical, fact-finding inquiry designed to create a clear and comprehensive record. The approach necessitates allowing the officer to provide their full account, then carefully and objectively examining the specific points of contention, whether they stem from a suspect's allegations of procedural error or from inconsistencies between a suspect's past and present statements. While officers are professional witnesses, their testimony regarding their own actions is, like any other, subject to rigorous scrutiny to ensure accuracy, consistency, and adherence to legal and procedural mandates. Ultimately, such inquiries are vital for upholding the integrity of the investigative process and ensuring that justice is administered fairly and transparently.