What is the exclusionary rule?
The exclusionary rule provides that evidence obtained without following lawful procedure cannot be used as evidence of guilt. In the United States it grew out of case law, from *Weeks v. United States* (1914) for federal courts to *Mapp v. Ohio* (1961) for the states. Korea codified it in Article 308-2 of the Criminal Procedure Act in 2007, effective 2008.
- Korea
- Criminal Procedure Act Art. 308-2
- US
- Weeks (1914), Mapp v. Ohio (1961)
- Purpose
- Deter illegal policing; protect due process and judicial integrity
- Extension
- Fruit of the poisonous tree
Why exclude reliable evidence?
If a seized item really is the murder weapon, should it be thrown out because the search was unlawful? The exclusionary rule answers yes. If illegally obtained evidence could be used, police would have an incentive to search without warrants or coerce statements. The rule puts constitutional due process ahead of fact-finding in individual cases.
Fruit of the poisonous tree
Evidence derived from an illegal search or interrogation is generally excluded as well. US courts recognize exceptions such as the good faith exception (*United States v. Leon*, 1984), inevitable discovery (*Nix v. Williams*, 1984) and independent source. Korea’s Supreme Court (2007Do3061, en banc) similarly allows derivative evidence in exceptional cases after weighing the violation and the causal link.
Comparison
| Country | Basis | Features |
|---|---|---|
| United States | Case law | Many developed exceptions |
| Korea | Statute (Art. 308-2) plus case law | Exceptions recognized by the courts |
| Japan | Supreme Court, 1978 | Excluded only for grave illegality that nullifies the warrant principle |
| China | Criminal Procedure Law Art. 56 | Coerced statements excluded; physical evidence excluded if defects cannot be cured or explained |
See also hearsay rule, Miranda v. Arizona and US criminal procedure.
Frequently asked questions
- What is the exclusionary rule?
- A rule barring the use of evidence obtained in violation of lawful procedure.
- What is the fruit of the poisonous tree?
- The doctrine that evidence derived from illegally obtained evidence is also excluded.
- Are there exceptions?
- Yes. In the US these include good faith, inevitable discovery and independent source.
References
- 형사소송법 제308조의2(위법수집증거의 배제), 법률 제8496호(2007. 6. 1. 개정, 2008. 1. 1. 시행).
- 대법원 2007. 11. 15. 선고 2007도3061 전원합의체 판결.
- Mapp v. Ohio, 367 U.S. 643 (1961).
- 最高裁判所第一小法廷 昭和53年9月7日判決, 刑集32巻6号1672頁.
- 《中华人民共和国刑事诉讼法》（2018年修正）第五十六条.