Proving Stimulant Offenses Without Seizing the Drugs: How Does Japan Handle "No-Substance" Cases?

In the prosecution of stimulant-related crimes, the ideal scenario for law enforcement is the seizure of the actual illicit substances. This physical evidence, when expertly analyzed, provides direct proof of the nature of the controlled drug involved. However, investigators often face situations where the stimulants that formed the basis of an alleged offense—such as past sales, acquisitions, or use—are no longer available for seizure. These are known in Japanese practice as mono-nashi jiken (物なし事件 – "no-substance cases"). This article explores how the Japanese legal system approaches the challenge of proving a stimulant offense when the primary physical evidence, the drug itself, is missing or only partially recovered.

The Guiding Principle: Proof Beyond a Reasonable Doubt, Not Solely by Seizure

The foundation of Japanese criminal procedure, like that of many other justice systems, is the requirement of proof beyond a reasonable doubt. Crucially, this high standard does not invariably demand the scientific analysis (鑑定 - kantei) of a seized substance to establish that a stimulant offense occurred. While such analysis is the most direct method, its absence is not necessarily fatal to the prosecution's case.

The Supreme Court of Japan, in a judgment on October 23, 1956 (Showa 31), acknowledged that for frequently encountered drugs like stimulants, identification does not exclusively depend on laboratory examination. The Court recognized that individuals with significant experience—such as law enforcement officers who regularly deal with such substances, or even habitual users and dealers—can often identify them based on appearance, packaging, effects, or common street names. This landmark ruling opened the door for courts to consider other forms of evidence to establish the nature of the substance in question. The overarching question remains whether the totality of the evidence presented leaves no reasonable doubt that the substance involved was, in fact, a prohibited stimulant as defined under the Stimulant Control Act.

Japanese courts and investigators typically encounter several types of "no-substance" or "partial-substance" scenarios:

Scenario 1: Partial Seizure – Some Drugs Recovered, Others Implicated from Past Transactions

A common situation arises when an individual is arrested for a current act of possession, and a quantity of stimulants is seized from them. During the subsequent investigation, the individual might confess to prior, uncharged incidents of acquiring or selling stimulants, often stating these drugs came from the same source or were part of the same batch as those seized. By this time, however, the drugs from these past transactions are usually consumed or otherwise unavailable.

In such cases, the prosecution's strategy involves:

1. Testimony of Involved Parties: Statements from the seller, the acquirer (the currently arrested individual), and any other relevant parties (e.g., intermediaries, other buyers from the same source) are crucial. These testimonies aim to link the unseized drugs from past transactions to the currently seized and analyzed drugs.
2. Establishing Consistency of Source and Nature: Evidence is gathered to demonstrate that both the seized drugs and the implicated unseized drugs originated from the same supplier, the same manufacturing batch, or were consistently treated and understood by all parties involved as being the same illicit substance.
3. Expert Analysis of Seized Drugs: The chemical analysis of the seized portion provides definitive proof of its nature as a stimulant.
4. Linking the Evidence: The core challenge is to persuasively establish the identity or, at minimum, a very strong and consistent similarity between the unseized drugs (from the past transactions) and the seized, analyzed drugs.

Several court precedents illustrate this approach:

• The Hiroshima High Court, on April 28, 1954 (Showa 29), dealt with a case where the accused had received a total of 14,300 ampoules of stimulants in multiple transactions over time. Only 13 ampoules from the final transaction were seized. The wholesaler testified to consistently supplying identical ampoules manufactured by a specific source. The accused also testified that all previously received ampoules were the same as the 13 seized ones. Coupled with the positive analysis of the seized ampoules, the court found sufficient evidence to conclude that all 14,300 ampoules were indeed stimulants.
• The Nagoya High Court, on April 28, 1955 (Showa 30), handled a case involving multiple acquisitions from the same supplier. While some drugs were seized, others related to earlier transactions were not. Testimonies from the accused and recipients frequently referred to the substance using common street names for stimulants, such as "Philopon injection liquid." The court, relying on this common understanding, the consistency of the drug source, and the analysis of the seized portion, determined that all transactions had involved stimulants.

Investigative Focus: In these partial seizure scenarios, it is vital for investigators to meticulously trace the origin of all implicated drugs and establish a clear common source or demonstrate consistent characteristics and handling that link the unseized substances to those that have been scientifically verified.

Scenario 2: No Drugs Seized, but Scientific Evidence Infers Their Prior Presence

In other instances, no bulk stimulants are recovered in relation to the specific charge, but scientific evidence from related items strongly infers their prior existence and handling. Common examples include:

• Drug Paraphernalia with Residue: Packaging materials like small plastic bags, paper wrappers, or containers used to hold stimulants are seized and found to contain microscopic trace residues of the drug. While the residue amount itself might be too small to constitute a separate, chargeable offense of possession, its presence is highly indicative of prior possession of a larger quantity.
• Contaminated Syringes: Syringes seized from a suspect or their premises test positive for stimulant residue, suggesting recent preparation and injection.
• Positive Urinalysis: A suspect's urine sample tests positive for stimulants or their metabolites. This scientifically confirms recent use, which, in turn, necessitates prior possession and administration of the drug.

The method of proof in these situations typically involves:

• Using the scientific findings (residue analysis from paraphernalia, urinalysis results) as potent circumstantial evidence. These findings strongly suggest that a chargeable quantity of stimulants previously existed and was possessed, used, or handled by the suspect.
• Corroborating this scientific evidence with any confessions from the suspect regarding the original amount of the drug, its source, how it was used or disposed of, and the timeline of these events. The scientific data serves to bolster the credibility of such confessions.

Court precedents support this approach:

• The Tokyo High Court, on February 22, 1956 (Showa 31), in a heroin case (with analogous principles), considered an envelope that had previously held heroin and still contained trace residues. The accused confessed to possessing a larger quantity (25g) and using it daily. The court held that the trace residue, combined with the detailed confession, was sufficient to corroborate the possession of the original 25 grams.
• The Osaka High Court, on May 17, 1957 (Showa 32), in a narcotics case, viewed a positive urinalysis for morphine and diacetylmorphine as indirect evidence supporting the defendant's confession of prior narcotics possession.
• The Osaka District Court, on February 15, 1990 (Heisei 2), upheld a conviction for possession of over 70 grams of stimulants with intent to sell, based on accomplice testimony and the discovery of empty packets with stimulant residue.

Investigative Focus: Investigators in such cases should prioritize seizing any items that might harbor trace evidence—packaging, weighing scales, spoons, cutting tools, and especially syringes. Detailed confessions regarding the original quantity, its acquisition, and its ultimate fate are critical. Collecting fingerprints from paraphernalia can also be vital in linking suspects to these items.

Scenario 3: No Drugs Seized and No Direct Scientific Evidence of the Substance Itself

This represents the most challenging scenario for prosecutors. Here, not only are the bulk stimulants missing, but there is also no direct scientific evidence from paraphernalia residues or urinalysis to specifically identify the substance involved in the alleged offense. Proof in these cases relies almost exclusively on testimonial evidence and other forms of circumstantial evidence.

Despite the difficulty, Japanese law does not automatically preclude a conviction. As the Supreme Court noted (October 23, 1956), identification by experienced individuals can be valid. The key is the overall strength and credibility of the combined evidence.

Courts have convicted based on:

• Testimony from Experienced Individuals:
  • In the aforementioned Supreme Court case of October 23, 1956, the defendant, a pharmaceutical company president, stated he could identify stimulants by sight. A drug broker testified that, based on his extensive experience, the items he bought from the defendant were undoubtedly stimulants. This, combined with testimony from another buyer, was deemed sufficient.
  • The Osaka High Court (April 19, 1955, subsequently upheld by the Supreme Court on January 12, 1956) relied on testimonies where both the seller (defendant) and the buyer referred to the traded items as "stimulants." The defendant also described the substance as white crystals with a bitter taste, consistent with stimulants.
  • The Tokyo High Court (September 21, 1955) considered a case where the defendant, an experienced user of "Philopon" (a common street name for methamphetamine), testified to recognizing the transacted items as Philopon. Testimony from recipients and intermediaries who had used a portion of the substance and experienced its characteristic stimulant effects was also crucial in identifying it.

To succeed in such highly challenging cases, prosecutors generally need to establish:

1. Reliable Identification by Knowledgeable Persons: Consistent and detailed testimony from individuals who, due to specific experience (e.g., long-term users, dealers, or even individuals with relevant professional backgrounds), could credibly identify the substance as stimulants based on its appearance, packaging, price, method of use, or experienced effects. The credibility of these witnesses is intensely scrutinized.
2. Corroboration Among All Key Participants: All essential parties involved in the alleged transaction (e.g., seller, buyer, any intermediaries) must consistently and credibly identify the subject matter of their dealings as stimulants.
3. Absence of Contradictory Evidence: There should be no significant evidence or circumstances suggesting that the substance could have been something other than stimulants (e.g., a different drug with similar appearance but different effects, or a non-controlled substance).

Investigative Imperative: While convictions are possible, the primary investigative strategy should always be to exhaust every avenue to seize the actual stimulants or, failing that, any physical items that can provide scientific linkage. It's also worth noting that even if the precise nature of a substance cannot be proven to be a specific stimulant, if an individual believed they were dealing with a regulated drug under incriminating circumstances, prosecution under separate provisions of the Narcotics Special Provisions Act might still be possible (as discussed in relation to mistake of fact).

Specific Considerations for Transfer/Acquisition Offenses with Unseized Objects

When the specific charge involves the transfer (jōto - 譲渡) or acquisition (jōuke - 譲受) of stimulants, and the transacted item itself is not recovered, proving its nature relies heavily on establishing an unbroken chain of evidence or identity with known, seized stimulants.

The common method is to link the unseized transacted item to other seized stimulants through a clear and consistent chain of testimony from all involved parties:

• Sequential Transactions: If A sells to B, and B subsequently sells to C, and drugs are seized from C, the testimony of A, B, and C can be used to establish that the drugs found on C are the very same drugs that passed from A to B, and then from B to C. This would prove the nature of the substance in the A-to-B transaction.
• Parallel Transactions from a Common Stash: If A sells a portion of a larger stash of stimulants to B, and another portion from the same stash to C, and drugs are seized only from C, the testimony of A, B, and C connecting A's original common stash to the drugs seized from C can be used to prove that what B received was also stimulants.
• Divided Batches: If A provides two bags of stimulants to B, and B gives one bag to C (from whom drugs are seized) and the other to D (from whom no drugs are seized), proving the nature of the drugs D received would involve testimony from all four. If A can confirm that both bags came from the same original, homogenous batch, the evidentiary link is stronger. If not, investigators would rely on consistent descriptions of the substance in both bags (appearance, color, packaging), the transaction price (consistent with stimulants), and importantly, any lack of complaint from D suggesting the substance he received was not what he expected (i.e., not stimulants).

Crucial Investigative Points for Unseized Transacted Items:

• Investigators must obtain highly detailed descriptions of the alleged stimulant (its form, color, packaging, quantity, price) from every individual involved in the unseized transaction.
• The timing of events is critical. The date and time of the alleged unseized transaction must be carefully compared with the date and time any related drugs were seized. If there is a significant time lag, or if evidence suggests that the seized drugs could have been obtained from an entirely different source unrelated to the unseized transaction, the chain of proof can be broken. Courts have acquitted defendants in cases where this link was deemed too tenuous or speculative.

Conclusion

Japanese law and judicial practice demonstrate a pragmatic approach to prosecuting stimulant offenses, even in challenging "no-substance" cases. While the seizure and scientific analysis of the actual drugs provide the most straightforward evidence, their absence is not an insurmountable obstacle if other forms of proof can establish the nature of the substance beyond a reasonable doubt.

Successful prosecution in such scenarios hinges on meticulous investigation aimed at:

• Linking implicated but unseized drugs to known, analyzed stimulants through a clear chain of custody or common origin, often reliant on consistent witness testimony.
• Utilizing scientific inference from trace residues on paraphernalia or through urinalysis to corroborate confessions of prior possession and use of larger quantities.
• In the absence of any physical or scientific trace, building a compelling case based on consistent, credible, and detailed testimonial evidence from individuals with demonstrable experience or knowledge of stimulants, corroborated by strong circumstantial evidence.

The overarching principle is that the totality of the evidence must be sufficiently compelling to convince the court of the defendant's guilt. This underscores the critical importance of thorough, resourceful, and multifaceted investigative work in every stimulant case, especially when direct physical evidence of the drug itself is elusive.