The Use of Agent Provocateur in Drug Offences and the Impact of Unlawfully Obtained Evidence on Court Proceedings

1. Introduction: The Test Purchase Method and the Core Issue

In combating drug offences, law enforcement units sometimes resort to the undercover officer or test purchase method. In this method, a public official acting as a buyer procures drugs from a specific individual; the suspect in the role of seller is then apprehended and criminal proceedings are instituted. Although the practice may appear at first glance to be an effective evidence-gathering tool, it gives rise to serious fundamental rights violations when it exceeds its legal limits.

The central question at the heart of the legal debate is: Is the police merely uncovering an offence already being committed, or is it — through its intervention — causing an offence to come into existence that would not otherwise have existed? The answer to this question directly determines the legal value of the evidence obtained and, ultimately, the fate of the accused. The established case-law of the Court of Cassation in this field makes it imperative that this boundary be observed with the utmost care.

2. Legal Basis and Limits of Undercover Officers

The primary statutory provision governing the assignment of undercover officers is Article 139 of the Code of Criminal Procedure (Law No. 5271). That provision expressly defines the duties and powers of the undercover officer and simultaneously delineates their limits:

CCP Art. 139/7: "For the purpose of preventing the offences committed by the organisation to which the undercover officer has been assigned, collecting evidence of those offences, and identifying the offenders, the undercover officer may establish contact with members of the organisation and participate in its activities. However, the undercover officer may not commit offences or participate as an inciter or aider in offences to be committed."

The final sentence of the provision is decisive: the undercover officer may not participate as an inciter or aider in the commission of an offence. This prohibition absolutely forbids the external creation of the mental element — one of the constituent elements of an offence — that is, the production by law enforcement of a criminal intent that did not previously exist in the perpetrator.

Furthermore, Supplementary Article 7 of the Police Powers and Duties Act (Law No. 2559) also imposes important limitations on the subject:

PPDA Supp. Art. 7: "Personnel assigned in an undercover capacity may gather information without inciting or encouraging persons to commit offences, for the purpose of identifying the offence and the offender and collecting evidence related to the offence..."

Both provisions point to the same principle: the law-enforcement officer may not exceed the role of passive observer. Paving the way for the commission of an offence, directing the perpetrator toward the offence, or offering the perpetrator an opportunity to commit an offence are plainly outside the limits drawn by statute.

3. The Concept of Agent Provocateur

In legal literature, an "agent provocateur" is defined as a public official or civilian informant who induces a person to commit an offence that the person had not previously intended or planned to commit. This definition is endorsed by the Court of Cassation's case-law and by academic doctrine, and has become the decisive criterion for determining whether the boundary has been exceeded.

The concrete indicators of agent provocateur activity may be listed as follows:

a) The criminal proposition is made by law enforcement to the perpetrator: The party initiating the request for drugs is not the perpetrator but the undercover officer.

b) The dialogue with the perpetrator is initiated by law enforcement: The perpetrator did not initiate contact; on the contrary, it was the law-enforcement officer who approached the perpetrator.

c) Persistent requests or attempts at persuasion: Cases in which the undercover officer puts forward more than a single request or attempts to persuade the perpetrator.

d) Absence of prior intelligence records regarding the perpetrator: The absence of concrete data previously obtained indicating that the person was involved in drug trafficking.

Where these conditions are met, the perpetrator's intent to commit the offence does not arise from free will but from the external intervention of law enforcement. Accordingly, the mental element of the offence has not in fact been realised.

4. Established Case-Law of the Court of Cassation

4.1. Agent Provocateur and Unlawfully Obtained Evidence

The 10th Criminal Chamber of the Court of Cassation has rendered numerous landmark decisions in this field. In its decisions, the Chamber has made it clear that evidence obtained in cases where the agent provocateur boundary has been exceeded cannot form the basis of a judgment, and that the accused must be acquitted.

"Where undercover officers, instead of merely observing and detecting the criminal act through passive conduct, have induced a person to commit an offence that person would not otherwise have committed, the evidence obtained cannot form the basis of the judgment." (Court of Cassation 10th Crim. Ch., File No. 2021/18463, Decision No. 2023/9107, dated 13.03.2023)

In another significant decision, the Chamber assessed the concrete circumstances of the case in detail and made the following finding:

"...it has been understood that the investigating undercover officers, instead of merely observing and detecting the criminal act through passive conduct, exhibited conduct designed to induce the person to commit an offence that person would not otherwise have committed — for the purpose of producing evidence and initiating an investigation — thereby exceeding the limits applicable to undercover officers and acting as an agent provocateur by inciting the perpetrator to commit the offence; accordingly, it has been considered unlawful to convict the accused instead of acquitting him." (Court of Cassation 10th Crim. Ch., File No. 2021/15492, Decision No. 2023/2074, dated 13.03.2023)

The 10th Criminal Chamber of the Court of Cassation has consistently reiterated the same principle in numerous decisions: File Nos. 2021/17420 – Dec. 2023/6284; 2021/17761 – Dec. 2023/9387; 2021/17496 – Dec. 2022/13453; 2022/5681 – Dec. 2024/17122; 2021/17170 – Dec. 2023/5998; 2023/22178 – Dec. 2024/562; 2022/10376 – Dec. 2024/15934.

4.2. Distinction Between Principal Offenders and Accessories

Another issue that frequently arises in drug offences is the correct determination of the boundary between principal offenders and accessories. According to the established case-law of the Court of Cassation on this point, a person who has no actual power of disposition over the drugs, who does not possess or transfer the substance, and who merely collects money or directs the buyer, must be characterised not as a principal offender but as an accessory within the scope of Article 39 of the Turkish Penal Code.

"In view of the act committed by the accused, consisting of directing a user who wished to purchase drugs to the other accused, it constitutes a ground for quashing that the accused's status as a principal offender was not qualified as 'accessory' and that the provision of Article 39, paragraph 2, subparagraph (c) of the TPC was not applied, resulting in the imposition of an excessive sentence." (Court of Cassation 20th Crim. Ch., File No. 2015/14771, Decision No. 2016/4471, dated 30.06.2016)

"Given that there is no evidence that the accused committed the act described in the statutory definition of the offence, that no drugs or stimulants were found on the accused's person, and that the accused directed drug users who called upon him to the other accused, it constitutes a ground for quashing that the act was not considered as falling within the scope of Article 39/2/c of the TPC and that the provision of Article 39/2/c of the TPC was not applied." (Court of Cassation 20th Crim. Ch., File No. 2017/5678, Decision No. 2018/469, dated 23.01.2018)

5. Elements of the Offence: Material and Mental Elements

5.1. Material Element: Control Over the Act

Pursuant to Article 188 of the Turkish Penal Code, the offence of drug trafficking may be committed through acts such as manufacturing, importing, exporting, selling, offering for sale, purchasing, accepting, transporting, or storing drugs or stimulants. In order to be a principal offender, one must personally carry out one of these acts or exercise joint control over the drugs. Punishing a person who has had no physical contact with, or power of disposition over, the substance as a principal offender is incompatible with the principle of legality.

5.2. Mental Element: Formation of Intent Through Free Will

In accordance with the fundamental principles of criminal law, a conviction for an offence may only be returned where the accused has freely decided to commit the offence. In the case of an agent provocateur, however, the accused reflects not an existing decision but a pressure of will imposed from outside. This demonstrates that the mental element has not in fact been realised.

6. Unlawfully Obtained Evidence and CCP Article 206/2-a

Article 38/6 of the Constitution provides: "Findings obtained in violation of law may not be admitted as evidence." This constitutional guarantee is transposed into procedural law by Article 206/2-a of the Code of Criminal Procedure (Law No. 5271):

CCP Art. 206/2: "A piece of evidence whose production is requested shall be rejected in the following cases: a) If the evidence has been obtained in violation of law..."

Evidence obtained through the agent provocateur method constitutes unlawfully obtained evidence within the framework of both the prohibition in CCP Art. 139/7 and the Constitutional provision at Art. 38/6. Such evidence must be rejected at the hearing, and may not form the basis of the judgment in the reasoned decision.

Indeed, the Court of Cassation 10th Crim. Ch. (File No. 2021/16961, Decision No. 2023/5881) held:

"...it has been understood that the undercover officers, without limiting themselves to passively observing the criminal act, exerted influence over the accused's will — at a stage when the accused was not yet preparing to commit a criminal act — by requesting drugs in a manner designed to incite the commission of an offence, for the purpose of reaching a result, that is, of collecting evidence; that the evidence thereby obtained is therefore unlawfully obtained evidence; and that, since unlawfully obtained evidence cannot form the basis of a judgment, it has been considered unlawful to convict the accused instead of acquitting him." (Court of Cassation 10th Crim. Ch., dated 22.06.2023)

7. The Principle of In Dubio Pro Reo (Benefit of the Doubt)

The principle of "in dubio pro reo" (benefit of the doubt) — one of the cornerstones of criminal procedure — requires that, for a conviction to be returned, the offence must be proven beyond any doubt. The source of this principle is the presumption of innocence developed by the European Court of Human Rights under Article 6 of the European Convention on Human Rights.

The Grand Criminal Chamber of the Court of Cassation has formulated this principle as follows:

"To convict an accused on the basis of a probability — however high — means rendering a judgment based on assumption rather than reaching the truth, which is the most important aim of criminal procedure." (Grand Criminal Chamber of the Court of Cassation, File No. 2017/718)

In drug offences, where no substance has been found on the accused, where the party who initiated the dialogue belongs to law enforcement, and where there is no concrete evidence previously indicating the accused's intent to commit the offence, all these conditions taken together give rise to reasonable doubt, which must be construed in favour of the accused.

8. Conclusion and Assessment

The use of the undercover officer (test purchase) method in drug-related cases does not in itself constitute a legal problem. The problem arises in situations where this method — by exceeding the limits of passive observation — creates the conditions for the formation of a criminal intent in the perpetrator that did not previously exist.

In this framework, the following principles stand out as the primary criteria:

• The undercover officer may only detect an existing offence; the officer cannot create an offence.

• Evidence obtained through the agent provocateur method cannot form the basis of a judgment pursuant to Article 38/6 of the Constitution and Article 206/2-a of the CCP.

• An accused who has no actual power of disposition over the drugs may be characterised not as a principal offender under Article 188 of the TPC but as an accessory under Article 39 of the TPC.

• In cases where it cannot be proved that the mental element of the offence was formed through free will, the principle of in dubio pro reo must be applied.

The requirement that the material truth be reached through lawful means in criminal proceedings is not merely an abstract expression. This principle draws boundaries around law enforcement activities, gives effect to constitutional guarantees in the evaluation of evidence, and ultimately provides the guarantee that innocent persons will not be convicted. From the perspective of the rule of law, the careful protection of these boundaries is not merely a matter of individual rights; it is also the fundamental basis of public trust in the judiciary.

References

• Code of Criminal Procedure (Law No. 5271, Articles 139, 206)

• Police Powers and Duties Act (Law No. 2559, Supplementary Article 7)

• Court of Cassation 10th Criminal Chamber, File No. 2021/18463, Decision No. 2023/9107, dated 13.03.2023

• Court of Cassation 10th Criminal Chamber, File No. 2021/15492, Decision No. 2023/2074, dated 13.03.2023

• Court of Cassation 10th Criminal Chamber, File No. 2021/16961, Decision No. 2023/5881, dated 22.06.2023

• Court of Cassation 20th Criminal Chamber, File No. 2015/14771, Decision No. 2016/4471, dated 30.06.2016

• Court of Cassation 20th Criminal Chamber, File No. 2017/5678, Decision No. 2018/469, dated 23.01.2018

• Grand Criminal Chamber of the Court of Cassation, File No. 2017/718

• Article 38/6 of the Constitution — Prohibition of unlawfully obtained evidence