Hello. This is Attorney Shin Joon-sun from Cheongchul Law Firm.

"I think my husband is having an affair, so I secretly recorded it; can this be used as evidence?" "I captured our KakaoTalk conversations, but I heard that they can't be used as evidence since they were obtained illegally?" Many people worry about what evidence can be accepted in cases of claims for damages due to the other spouse's infidelity. Does the exclusionary rule for illegally obtained evidence from criminal proceedings also apply to civil and family lawsuits?

This is not necessarily the case. Therefore, even evidence obtained by secretly recording the other party or checking messages can be recognized as admissible evidence. However, if you violate specific provisions like the Communication Privacy Protection Act, evidence may be excluded from being admitted in exceptional cases, and you may face criminal penalties or liability for damages in the process of collecting evidence. This article will examine the criteria for determining the admissibility of illegally obtained evidence in family lawsuits and practical considerations.

[Question] In order to prove my spouse's infidelity, I need to collect secret evidence; can this kind of evidence be used in court?

[Answer]

1. Criminal Lawsuit vs. Civil Lawsuit: Differences in Applicable Standards

a. Exclusionary Rule for Illegally Obtained Evidence in Criminal Law

Article 308-2 of the Criminal Procedure Act states, "Evidence collected without following due process cannot be used as evidence." This is because investigative agencies collect evidence from a superior position, backed by state power, which raises significant concerns about the potential infringement of fundamental rights of the public, making it unlikely that they can effectively suppress this breach (Supreme Court ruling 2020.11.26, 2020Do10729).

b. Civil and Family Lawsuits are Different

On the other hand, the Civil Procedure Act adopts the principle of free evaluation of evidence (Article 202 of the Civil Procedure Act) and does not have explicit restrictive provisions regarding admissibility like the Criminal Procedure Act. Article 12 of the Family Procedure Act also states that "If there are no special provisions in this law regarding the procedure of family litigation, the provisions of the Civil Procedure Act shall apply," indicating that the principle of free evaluation of evidence of the Civil Procedure Act is also applied in family lawsuits.

The Supreme Court has also ruled that, under our civil procedure law, which adopts the principle of free evaluation of evidence, one cannot conclude that a recording of a conversation with the other party in secret has no evidentiary value solely based on that fact; rather, whether the evidence is admissible falls under the discretion of the fact-finding court (Supreme Court ruling 1999.5.25, 99Da1789).

c. Why Is There a Different Standard in Civil Lawsuits?

Civil lawsuits are procedures to resolve disputes between parties on equal footing. Unlike criminal lawsuits, where state power unilaterally collects evidence, parties must collect and prove evidence directly. Especially in family lawsuits, to prove a spouse's infidelity, the parties must collect evidence themselves; stringent restrictions on evidentiary admissibility could make it virtually impossible to seek legal remedies. Therefore, the importance of discovering the substantive truth and protecting rights is recognized as being much greater.

2. Cases Where Admissibility Is Recognized: Recording of Conversations with the Parties Involved

a. Key Distinction Criteria: Whether It Is a "Conversation with Others"

Article 14, Paragraph 1 of the Communication Privacy Protection Act prohibits the recording of "unrevealed conversations between others." Here, the important factor is the phrase "between others." Recording a conversation with the other party without their knowledge does not count as recording a "conversation between others," thus not violating the Communication Privacy Protection Act.

b. Practical Examples

Therefore, directly conversing with your spouse while secretly recording that conversation is legal. For example, if you confront your spouse about infidelity while recording that conversation, or record your spouse admitting their infidelity, this can be used as evidence.

3. Cases Where Admissibility Is Denied: Recording of Conversations Between Others

a. Explicit Provisions of the Communication Privacy Protection Act

The situation is different if a third party secretly records a conversation between others. Violating Article 14, Paragraph 1 of the Communication Privacy Protection Act leads to the explicit provision under Article 14, Paragraph 2, which states, "Cannot be used as evidence in judicial or disciplinary proceedings."

b. Real Case: Vehicle Black Box Recording Incident

Recently, there was a case where this issue was seriously addressed in a lower court. The plaintiff (spouse) submitted evidence from a vehicle black box that recorded a conversation between the defendant (the other spouse) and a third party to prove the defendant's infidelity, claiming divorce and damages.

The first instance court recognized the admissibility of the recorded evidence and accepted the defendant's infidelity, fully granting the claim for damages. However, viewing the plaintiff's method of evidence collection as a violation of the Communication Privacy Protection Act, the court partially accepted the defendant's claim for damages, ordering compensation of 500,000 won.

However, the second instance court determined that the plaintiff's secret recording of the conversation between the defendant and the person involved in the infidelity as a third party violated Article 14, Paragraph 1 of the Communication Privacy Protection Act, ruling that it was not admissible. Nonetheless, by considering other evidence (KakaoTalk messages, witness statements, etc.), the court acknowledged the defendant's infidelity but reduced the amount of damages as the specific contents and degree of infidelity could not be fully established without the recorded evidence.

4. Legal Risks in the Evidence Collection Process

a. Criminal Responsibility

If you violate the Communication Privacy Protection Act, the Personal Information Protection Act, or the crime of trespassing while collecting evidence, you may face criminal penalties. Specifically, if you violate Article 14, Paragraph 1 of the Communication Privacy Protection Act by recording a conversation between others, you could face imprisonment for up to 10 years or disqualification for up to 5 years under Article 16, Paragraph 1, Subparagraph 2 of the same law. Caution is essential, as the situation may arise where you face criminal penalties while trying to prove infidelity.

b. Civil Responsibility

If you infringe on the rights of the other party during the collection of evidence, they may claim damages for illegal acts (Article 750 of the Civil Act). In the previously mentioned vehicle black box recording case, the first instance court recognized damages of 500,000 won. Thus, an ironic situation may occur where one seeks damages for infidelity while concurrently facing damages due to methods of evidence collection.

5. Practical Considerations

a. Record as a Party to the Conversation

It is safest to collect evidence as a party to the conversation whenever possible. Recording the conversation directly with your spouse does not violate the Communication Privacy Protection Act, therefore, its admissibility as evidence is recognized, and there is no risk of criminal prosecution.

b. Secure Various Types of Evidence Together

In preparation for the possibility that the admissibility of recorded evidence may be denied, it is necessary to secure other evidence, such as KakaoTalk messages, emails, photos, and witness statements. In the earlier case, while the recorded evidence was excluded, infidelity was acknowledged through other evidence.

c. When Checking Mobile Phone Messages

Secretly checking or capturing the other party's mobile phone messages does not fall under the