CONTENTS
- 1. Evidence Collection | The Principle of Admitting Only Lawfully Collected Evidence
- - The Case of Former Assembly Member Noh Woong-rae's Receipt of Bribes and Political Funds
- - The Case of Entering a Residence Without a Warrant and Conducting a Breathalyzer Test
- 2. Evidence Collection | The Key Issues in the Two Cases
- - Legal Significance and Implications
- 3. Evidence Collection | Response Strategies When Asserting That Evidence Was Illegally Obtained
- - If You Need an Attorney's Assistance in the Evidence Collection Process
1. Evidence Collection | The Principle of Admitting Only Lawfully Collected Evidence
In November 2025, two judgments were pronounced that once again emphasized the principle that only lawfully collected evidence is admitted in criminal justice proceedings.
One was a case in which a member of the National Assembly was alleged to have received tens of millions of won in bribes and political funds, and the other was a case in which the defendant had confessed to drunk driving.
Although the nature of the offenses differed, both cases reached the same conclusion that illegally collected evidence cannot be used in court and that all secondary evidence collected on its basis likewise loses its admissibility.
The Case of Former Assembly Member Noh Woong-rae's Receipt of Bribes and Political Funds
Noh Woong-rae, a former member of the National Assembly affiliated with the Democratic Party of Korea, was indicted on charges of receiving a total of 60 million won from a person surnamed Park during 2020 under the pretexts of brokering permits and licenses for a logistics center, providing favors for a power plant supply project, and providing favors related to a solar power project.
The prosecution determined that some of this had been provided as election funds immediately before the general election and as intra-party election expenses, and accordingly applied charges of receipt of bribes, acceptance of a bribe through mediation, and violation of the Political Funds Act. After indicting him without detention in March 2023, the prosecution sought four years' imprisonment, a fine of 200 million won, and collection of an equivalent value of 50 million won at the final hearing.
To prove the defendant's charges, the investigative agency collected evidence by seizing various electronic devices and analyzing mobile phone data.
However, the court noted that information secured during the digital forensics process had been used in the investigation of a different crime from the one for which the warrant had originally been issued.
In other words, the court determined that the electronic information on the mobile phone had been collected arbitrarily in a manner exceeding the scope of the warrant, and that the prosecution had constructed the charged facts by securing additional statements and supplementary evidence on that basis.
Accordingly, the Seoul Central District Court determined that the material in question constituted illegally collected evidence and excluded its admissibility in full.
The court also excluded all of the secondary evidence, on the ground that statements derived from the unlawful search and seizure likewise could not function as independent evidence.
In the end, no lawful evidence remained to support the charged facts, and the court acquitted former Assembly Member Noh.
The Case of Entering a Residence Without a Warrant and Conducting a Breathalyzer Test
A was indicted on charges of having driven a stretch of about 300 meters on the night of April 1, 2024, with a blood alcohol concentration of 0.076%.
The police, responding to a report, confirmed that A had already arrived at the residence and parked the vehicle, after which they entered A's residence without a separate warrant and conducted a breathalyzer test.
In the course of this, the police did not explain basic matters required to be advised, such as the right to refuse entry or the right to request the officers to leave.
Although A confessed to drunk driving, it was also confirmed that, on the same occasion, A had protested to the effect of "Is it right to question me at my home?", "Isn't this trespassing on a residence?", and "I drank again after coming home."
The structure became such that the credibility of A's confession could only be assessed together with the lawfulness of the investigative procedure, and in the end the Changwon District Court determined that the police's entry into the residence and the breathalyzer process had exceeded the scope of voluntary investigation, and that there were no circumstances justifying it on grounds of urgency or the prevention of danger.
Accordingly, the breathalyzer result constituted illegally collected evidence, and because no other lawful evidence existed to corroborate A's confession, A was acquitted.
2. Evidence Collection | The Key Issues in the Two Cases
Although the offenses differ, both cases follow the same legal structure.
1. A violation of the warrant requirement goes beyond a procedural defect and amounts to an "infringement of the essence."
- A mobile phone is a representative area of highly concentrated privacy.
- A residence is the space most strongly protected under the Constitution.
Accordingly, an unlawful search and seizure in either of these areas necessarily results in a limitation of admissibility.
2. The "fruit of the poisonous tree" principle
The fruit of the poisonous tree doctrine, meaning "a poisonous tree bears poisonous fruit," is a theory explaining that statements, reports, and additional evidence created on the basis of information obtained through an unlawful search and seizure all lack admissibility.
The reason the statement evidence was excluded in the case of former Assembly Member Noh was also a determination following that principle.
3. A "confession without corroborating evidence" cannot result in conviction.
In A's drunk driving case as well, the reason an acquittal resulted despite a confession to drunk driving is that, where all the corroborating evidence is illegally collected material, guilt cannot be inferred from the confession alone.
Legal Significance and Implications
Criminal Procedure Act, Article 215 (Seizure, Search, and Inspection) A prosecutor may conduct a seizure, search, or inspection by a warrant requested from and issued by a judge of the district court, limited to cases that (1) are necessary for the investigation of a crime, (2) involve circumstances giving rise to a suspicion that the suspect has committed an offense, and (3) can be recognized as relevant to the case concerned.
Criminal Procedure Act, Article 308-2 (Exclusion of Illegally Obtained Evidence) Evidence collected without following due process shall not be used as evidence.
Compliance with due process in collecting evidence is, beyond a formal requirement, a necessary element that constitutes the substantive legitimacy of criminal justice.
The moment evidence secured in violation of procedure is permitted, the authority of investigative agencies loses its checks, and the risk of infringing citizens' fundamental rights increases.
These judgments are cases that reaffirm in practice the constitutional principle that prioritizes the protection of fundamental rights, and it appears that compliance with the scope of warrant execution and with procedure will be required even more strictly in future investigations.
3. Evidence Collection | Response Strategies When Asserting That Evidence Was Illegally Obtained
If, in a criminal case, it is determined that evidence was illegally collected, one may consider asserting acquittal or the like through strategies such as the following.
1. Review the scope of the search and seizure warrant
When a search and seizure or digital forensics is conducted, one must verify whether the scope, period, and target of the warrant are accurately stated.
Because the scope of a warrant is interpreted especially narrowly for devices in which privacy is concentrated, such as mobile phones and computers, the analysis of material outside that scope loses its admissibility.
2. Securing the lawfulness of the statement process
Where the questioning and statement process of an investigative agency is combined with unlawful procedures, such as coercion, omission of required advisements, or violations of the procedure for entering a residence, the statement itself may not be used as evidence.
It is important to record in detail the circumstances before and after the statement, whether advisements were given, and whether the statement was voluntary.
3. Examination of corroborating evidence
Even if a confession exists, conviction is difficult where there is no lawful evidence to corroborate it, so it is necessary to examine through what procedures the evidence secured at the early investigation stage was obtained.
4. Assistance from professionals in evidence collection and from an attorney
Because it is difficult for laypersons to determine whether evidence was illegally collected, matters such as the presentation of the search and seizure warrant, the lawfulness of the forensic procedure, and the legal requirements for a search of a residence are best analyzed by professionals.
If You Need an Attorney's Assistance in the Evidence Collection Process
If you become involved in a case where a procedural violation by an investigative agency is suspected, it is necessary to review, from the early stage of the investigation, the scope of the search and seizure, the lawfulness of the forensic procedure, and the voluntariness of the statement-formation process.
In particular, where a defect is found in the procedural requirements of the process of analyzing electronic information, such as on mobile phones and computers, it can shake the evidentiary structure of the entire case.
At Daeryun Law Firm, attorneys handling criminal matters collaborate with the Evidence Examination Center and the Digital Forensics Center to systematically develop a defense strategy centered on whether evidence was illegally collected.
If you are in a situation where a procedural violation is suspected in the evidence collection process, please seek the assistance of a professional as early as possible to establish a response strategy.
