How can you effectively impeach a witness in a Japanese criminal trial using their prior inconsistent statements?

Japanese Attorney at Law - Bengoshi L.L.

• 7 min read

Cross-examination is a critical phase in any criminal trial, offering the opportunity to test the veracity of a witness's testimony. One of the most potent tools in an advocate's arsenal for this purpose is the use of a witness's own prior inconsistent statements (jiko mujun kyōjutsu). In the Japanese criminal justice system, where pre-trial written statements prepared by investigators often play a significant role, effectively highlighting inconsistencies between such statements and live courtroom testimony can be pivotal in diminishing a witness's credibility (dangai). This process, however, is not a haphazard affair; it requires a structured, disciplined approach to maximize its impact.

The Foundation: Why Prior Inconsistent Statements Matter in Japan

In Japan, the investigative process often results in detailed written documents, known as chosho, which are essentially narrative statements compiled by police officers or public prosecutors based on their interviews with witnesses or suspects. These documents are typically read to or by the individual, who then signs or affixes their personal seal to attest to their accuracy.

When a witness later testifies in court and their live account deviates from what is recorded in their earlier, formally adopted chosho, an immediate question of reliability arises. Is their current memory faulty? Was their previous statement inaccurate or coerced? Or is their current testimony tailored for the courtroom? The cross-examiner's objective is to strategically expose this deviation to the fact-finders (professional judges and, in applicable cases, lay judges, or saiban-in), thereby casting doubt on the witness's overall credibility. The goal of this specific impeachment technique is to demonstrate unreliability through inconsistency, rather than necessarily to prove the substantive truth of the prior statement via the act of impeachment itself (though under certain Japanese evidentiary rules, some prior inconsistent statements, particularly those made to a prosecutor, might be admitted as substantive evidence if specific conditions are met, such as under Article 321, Paragraph 1, Item 2 of the Code of Criminal Procedure).

The Strategic Framework: The 3 Cs of Impeachment (Commit, Credit, Confront)

A highly effective and structured method for impeaching a witness with a prior inconsistent statement, recognized internationally and increasingly emphasized in Japanese advocacy training, is often encapsulated by the "3 Cs": Commit, Credit, and Confront. This methodical approach ensures that the inconsistency is presented with maximum clarity and impact.

Step 1: COMMIT – Solidifying the Current Testimony

Before an inconsistency can be effectively demonstrated, the witness must be unequivocally "locked into" their current, in-court testimony on the specific point that will be challenged. This "Commit" phase aims to leave no room for ambiguity or later claims of misinterpretation.

  • Purpose: To ensure the witness clearly and firmly states their present position on the fact in question.
  • Techniques: This is achieved through precise, closed-ended leading questions that compel the witness to reaffirm the specific assertion made during their direct examination or earlier in the cross-examination.
    • Example: "Mr. Yamada, you testified just a few minutes ago that you saw the defendant exit the building at precisely 10:00 PM. Is that correct?"
  • Importance: This step prevents the witness from later attempting to backtrack by claiming they were misunderstood in court, or that their current testimony wasn't as definitive as the cross-examiner suggests. It sets a clear, current benchmark against which the prior statement will be contrasted.

Step 2: CREDIT – Validating the Circumstances of the Prior Statement

Once the witness is committed to their present testimony, the next crucial step is to "Credit" the prior statement. This does not mean asking the witness if their prior statement was true (which would be an open invitation for them to affirm their current, differing testimony). Instead, it involves establishing the circumstances under which the prior statement was made, in a way that highlights its seriousness, the witness's opportunity for accuracy, and their formal adoption of it at that time.

  • Purpose: To make it difficult for the witness to subsequently dismiss their prior statement as trivial, mistaken, coerced, or not properly recorded. The aim is to show that, at the moment the prior statement was made or adopted, the witness had reason and opportunity to ensure its accuracy.
  • Techniques: This involves a series of leading questions about the context of the prior statement:
    • Confirming when, where, and to whom the statement was given (e.g., "Do you recall giving a statement to Investigator Tanaka at the police station on March 15th?").
    • Highlighting the temporal proximity to the events, suggesting memory was fresher ("That was just two days after the incident you've described, wasn't it?").
    • Affirming the witness’s understanding of the importance of being truthful to the investigator ("You knew it was important to provide Investigator Tanaka with an accurate account, correct?").
    • Detailing the formal process of the statement's creation and adoption ("Investigator Tanaka typed up what you said, didn't he?" "And after he prepared the document, you were given the opportunity to read it through, or he read it to you, to ensure it was correct?" "And you then signed this document, here at the bottom of each page, to confirm its contents were accurate as far as you were concerned at that time, did you not?").
  • Navigating Japanese Specifics (The Chosho Context):
    • Investigator-prepared statements (chosho) in Japan are unique. They are often lengthy narratives, sometimes compiled over several interview sessions. The "Credit" phase for such a document needs to acknowledge this process.
    • A significant challenge for defense counsel is that aggressively "crediting" a prosecutor-prepared statement (kensatsukan chosho) might inadvertently support the prosecution's argument for its substantive admissibility under the "special circumstances assuring credibility" (tokushin jōkyō) doctrine. Therefore, the focus during the "Credit" phase by the defense is very precisely on the witness's actions and affirmations at the time of the statement's creation (e.g., they signed it, they had a chance to correct it) rather than an endorsement of its inherent truthfulness for the current proceedings from the defense's perspective. The aim is to establish that the witness vouched for its accuracy then, making their current deviation problematic for their credibility.

This meticulous groundwork is sometimes referred to in Japanese advocacy as "tame o tsukuru" – creating a build-up or setting the stage. By firmly establishing the witness's current testimony and the formal, seemingly reliable circumstances of their prior statement, the advocate closes off potential "escape routes" before the actual confrontation.

Step 3: CONFRONT – Exposing the Inconsistency

With the foundation laid, the advocate moves to the "Confront" phase, where the prior inconsistent statement is directly presented to the witness and, crucially, to the court.

  • Purpose: To clearly and undeniably demonstrate the contradiction between the witness's current testimony and their prior statement.
  • Techniques:
    • Proper Introduction of the Document (if using a written statement): The advocate may seek to show the relevant document to the witness. In Japan, Criminal Procedure Rule 199-10 allows for documents to be shown to a witness concerning their authenticity, identity, or similar matters. This is distinct from Rule 199-11, which pertains to refreshing a witness's memory and generally restricts the use of their own prior narrative statements for that specific purpose to avoid circumventing hearsay rules. If the document is not yet in evidence, opposing counsel must typically be given an opportunity to inspect it beforehand.
    • Directing to the Specifics: The witness should be directed to the precise page and line number of the contradictory portion.
    • The Advocate Reads the Passage: To maintain control, ensure clarity, and deliver the appropriate emphasis, it is generally recommended that the cross-examining lawyer reads the relevant excerpt from the prior statement aloud.
      • Example: "Mr. Yamada, you affirmed a moment ago that you testified in court today that you saw the defendant leave at 10:00 PM. I am now showing you your signed statement to Investigator Tanaka dated March 15th. Looking at page 3, paragraph 2, did you not state at that time, 'I saw the defendant leave the building at approximately 11:00 PM'?"
    • Confirmation of the Contradiction: The question following the reading should be a simple, leading one, asking the witness to confirm that the document indeed contains that contradictory information. "That is what your statement says, isn't it?"

The impact lies in the stark, undeniable nature of the inconsistency itself, laid bare after the careful build-up.

After the Confrontation: The Critical Art of Restraint

Once the inconsistency is clearly exposed, a common temptation is to press the witness further: "So, were you mistaken then, or are you mistaken now?" or, more aggressively, "Which time were you lying?" Perhaps the most tempting of all is to ask, "Why is your testimony different today?"

However, a cornerstone of disciplined impeachment technique is to avoid these follow-up questions, especially the "Why."

  • Giving Away Control: Asking "Why?" hands control back to the witness, allowing them to offer explanations, excuses (e.g., "I was confused then," "The investigator pressured me," "I remembered more clearly later"), or justifications that can dilute the impact of the impeachment.
  • The Power of the Unexplained Contradiction: The inconsistency itself, standing unexplained by the witness during cross-examination, is often far more damaging to their credibility. The lawyer's job is to reveal the contradiction; the fact-finders can draw their own conclusions about its cause and implications.
  • Argument, Not Evidence: The reasons for the inconsistency and its impact on the case are matters for the lawyer to argue in their closing statement, armed with the established contradiction.
  • The Danger of Dame o Osu Na: This Japanese advocacy aphorism means "Don't push for the extra point" or "Don't gild the lily." Once the impeachment point is made, moving on is often the most effective strategy. Over-cross-examining on a successful point can diminish its effect or give the witness an opening.

Procedural Considerations for Using Written Statements in Japan

When using a prior written statement for impeachment in a Japanese court:

  • Clarity on Purpose: It's crucial to be clear that the statement is being used for impeachment regarding an inconsistency, not (by the defense) to prove the truth of its contents or (by either side) to improperly refresh recollection in a way that circumvents evidence rules.
  • Maintaining Control in Presentation: As mentioned, the examining attorney should generally read the pertinent section of the statement. This prevents the witness from selectively reading, misreading, or launching into an explanation while supposedly just reading. The lawyer can control the pace and ensure the fact-finders hear the exact words of the inconsistency.

What if the Witness Denies the Prior Statement or its Accuracy?

If, during the "Credit" or "Confront" phase, the witness denies making the prior statement, claims it was inaccurately recorded despite their signature, or alleges coercion, this doesn't necessarily mean the impeachment has failed.

  • If the "Credit" phase was handled effectively (establishing their signature, opportunity to review, etc.), such denials can themselves appear incredible and further damage the witness's credibility.
  • The lawyer will have laid the foundation to potentially introduce further evidence later to prove the statement was indeed made as recorded (for example, through the testimony of the investigator who took the statement, though this raises further strategic considerations).
  • The immediate goal of the impeachment sequence during the witness's cross-examination is to demonstrate the inconsistency or the witness's current unreliability concerning their own prior formal declarations.

Conclusion

Effectively impeaching a witness in a Japanese criminal trial using their prior inconsistent statements is a systematic and disciplined art. It is not about surprising the witness with a "gotcha" moment out of the blue, but about a meticulous, step-by-step deconstruction of their credibility. The 3 Cs—Commit, Credit, and Confront—provide a robust framework. This, combined with the strategic use of leading questions, a keen understanding of the unique role of chosho, and the crucial discipline of restraint after the contradiction is exposed, allows an advocate to powerfully challenge testimony and fulfill their duty within the Japanese criminal justice system. Mastering this technique requires not only intellectual rigor but also a deep appreciation for courtroom dynamics and the psychology of testimony.