One of the most frequently encountered digital evidence in today's criminal trials is correspondence in instant messaging applications such as WhatsApp, Telegram, Signal, iMessage. Both the victim and the defendant often add these correspondences (as screenshots) to the files; However, how this evidence was obtained legally, its accuracy, and whether it was manipulated or not leads to serious debates. In this article, the basic legal framework of the issue and the approach of the Supreme Court are discussed.
Reminder: For informational purposes only; The evaluation of digital evidence in the concrete case depends on the judge's discretion and the conditions specific to the file.
Legal Framework
Constitution Article 22 guarantees freedom of communication; Article 20 protects privacy. CMK article 135 requires a judge's decision to detect, listen to and record the communication. Constitution Article 38/6: "Findings obtained illegally cannot be accepted as evidence."
These provisions make how messaging correspondence is obtained critical in terms of evidence law.
Obtaining Messaging Correspondence through Lawful Means
1) Party Submission of Its Own Correspondence
The person who is a party to the correspondence (victim or defendant) can bring the correspondence on his or her device to court. In this case, there can be no violation of freedom of communication; because it is the party to the correspondence.
2) Device Examination by Judge's Decision
Upon the request of the public prosecutor, the judge may decide to seize the defendant's device and conduct forensic computer examination (CMK art. 116-127). Correspondence obtained in accordance with this procedure can be used as evidence.
3) Interception of Communication (CMK article 135)
It can only be done in terms of catalog crimes listed in the law and by a judge's decision. Time is limited.
Correspondence Obtained Through Unlawful Means
As a rule, correspondence obtained through the following methods cannot be used as evidence:
- Correspondence obtained by accessing your spouse/lover's phone without notice
- Correspondence taken from a third party's device without a judge's decision
- Correspondence obtained by stealing or taking the device by force
- Unannounced examination of correspondence regarding the employee's private life, even if he/she has a work phone
In its consistent jurisprudence, the Criminal General Assembly of the Supreme Court of Appeals has emphasized that illegally obtained digital evidence cannot be used within the framework of the "fruit of the poisonous tree" doctrine.
Screenshot Insufficiency
A frequently made mistake; Applying to the judiciary only with a screenshot. However, the evidentiary value of the screenshot is limited:
- Screenshots can be easily manipulated (fake message can be added, name can be changed).
- When the other party claims "this correspondence does not belong to me", it is difficult to prove it with a screenshot.
- If the defendant deletes the correspondence, the authenticity of the screenshot cannot be confirmed.
Practical suggestion: A notarized detection for messaging evidence or a report obtained through a computer forensic examination of the device increases the evidentiary value.
Forensics Examination
The image of the device is taken by the forensic computer expert/expert, the hash value is recorded and it is determined whether the correspondence exists on the original device and whether it has been manipulated. The process consists of these steps:
WhatsApp Web and Backups
Logging in to another device via WhatsApp Web makes it possible for a third party to access correspondence. Correspondence obtained in this case:
- Lawful if there is explicit consent of the owner
- Spouse/partner's unannounced login is illegal evidence
The same rules apply for cloud backups (iCloud, Google Drive); Access without the consent of the account holder is against the law and may constitute a crime under Article 243 of the Turkish Penal Code.
Precedent Decisions (Reference)
- Criminal General Assembly of the Supreme Court - ByLock and Encrypted Messaging: In the CGK decisions regarding the use of ByLock, the technical process of obtaining digital evidence by lawful methods, the accuracy of its content, and the concrete identification of the user were meticulously evaluated. It is emphasized that server record matching alone cannot be considered sufficient and that the matching must be concretely proven.
- 16th Criminal Chamber of the Supreme Court of Appeals - WhatsApp Correspondence: In the files where the correspondence was presented with screenshots, the original was sought to be confirmed by forensic computer analysis on the device. It is emphasized that correspondence obtained illegally cannot be used as evidence.
- Supreme Court 4th Civil Chamber - WhatsApp in Divorce Cases: Even in civil proceedings, there are precedents stating that correspondence obtained by the spouse by accessing the other's phone without their knowledge is not accepted as evidence. The principle that illegal evidence cannot be accepted in civil proceedings has been established.
- 12th Criminal Chamber of the Supreme Court of Appeals - Violation of Personal Data: It has been emphasized that receiving and sharing someone else's correspondence without permission constitutes a crime within the scope of TCK Articles 135-136.
- Constitutional Court - Freedom of Communication: The Constitutional Court has determined in various decisions that obtaining messaging content through unlawful means is a violation of Article 22 of the Constitution (freedom of communication).
Elements Required for the Reliability of Messaging Evidence
- Conversation found on original device (not screenshot)
- Confirmation that there is no manipulation with forensic report
- Correct identification of the sender and recipient of the correspondence (phone number, account verification)
- The correspondence must have been obtained in accordance with the law
- Knowing the context of the correspondence (before/after messages)
Practical Reminders
Conclusion
Messaging correspondence has become one of the indispensable types of evidence in today's criminal proceedings. However, this evidence; It is taken into consideration by the court if it is obtained in accordance with the law, originality is confirmed and supported by digital forensics. The evidence value may be weak in files based solely on screenshots. Correspondence obtained through illegal means cannot be used as evidence in accordance with Article 38/6 of the Constitution. The outcome is specific to the file and depends on the judge's discretion.