The prosecutor's appeal is dismissed.

1. The reason for appeal that a police officer of the instant case moves to a police box with the defendant to measure the alcohol of the defendant constitutes legitimate voluntary movement.

Even if there was a problem in the process of voluntary behavior, it does not constitute a violation of the substantial contents of due process. Thus, the report on the statement of the status of the driver, which is the second evidence collected after the defendant was sent to the police box, shall be admissible.

The judgment of the court below which acquitted the Defendant of the facts charged of this case is erroneous by misapprehending the legal principles.

2. Determination 1) Article 199(1) of the Criminal Procedure Act explicitly states the principle of voluntary investigation. Being accompanied by an investigator to an investigative agency, etc. in the form of a consent obtained in the course of an investigation does not have any means to restrain the physical freedom of a suspect even though it is substantially similar to the arrest, and thus, it is not systematically and practically arbitable. Moreover, it is highly likely to bring about a result contrary to the principle of the Criminal Procedure Act, such as not providing various rights guarantee devices granted to a suspect arrested and detained by the Constitution and the Criminal Procedure Act on the ground that it is prior to the regular arrest and detention phase. Therefore, it is reasonable to view the legality of accompanying to a suspect solely based on objective circumstances, such as where the investigator knew that he/she could refuse accompanying the suspect prior to the accompanying phase, or where it is recognized that the suspect may freely leave or be accompanied at any time by the investigative agency, etc., was accompanied by the suspect’s voluntary will, and it is evident that the warrant of accompanying was duly established (see, e.g., Supreme Court Decision 2009Do6786.