Investigative measures based on the consent

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K01347
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 05050:Criminal law-related
• Research Institution: Kyoto University
• Principal Investigator: Ikeda Kimihiro 京都大学, 法学研究科, 教授 (70302643)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 刑事訴訟法 / 捜査法 / 任意捜査 / 同意

Outline of Final Research Achievements

This research examined how to determine whether the consent to the implementation of investigative measures by persons subject to criminal investigation exists or not, as well as how to evaluate its effectiveness. In a case where a person cannot know that a certain measure is implemented secretly, his consent cannot exist, because there is no opportunity to give any consent. On the other hand, as long as a person recognizes the existence of a certain explicit measure and the right that should be restricted, he can give consent to its implementation and its effectiveness should not be denied, even if he doesn't know that the measure is carried out by an investigative officer, and then the measure is not coercive.

Free Research Field

刑事訴訟法

Academic Significance and Societal Importance of the Research Achievements

捜査対象者の同意を得て行う任意捜査は、柔軟かつ迅速に捜査目的を達成することを可能にし、実務上果たす役割が大きい一方、同意の存否や射程、および有効性は、実施された捜査手法の適否の評価に影響する。本研究は、同意の存否等の判断において考慮されるべき事情と、その持つ意味について検討を加え、任意捜査の適否の評価基準を明確化することを通じて、実務の効率化のみならず適正化に資するものといえる。また本研究の成果は、捜査対象者の協力が法的に義務付けられる形態の強制処分の実効性確保のあり方についても示唆を与えるものといえる。