The prosecutor's appeal is dismissed.

1. At the time of the instant case, the Defendants assaulted police officers who lawfully perform their duties for the purpose of assembly management, and the lower court acquitted all of the charges of this case on the ground that the duties performed by police officers are not legitimate.

2. In the trial of the court, the prosecutor of this court requested changes in the indictment of this case that "as 300 career people who had been in the factory, 400 union members who had been in the factory and 600 outside people who had attempted to enter the factory inside the factory for intra-company joint and several meetings, including 200 outside people who had attempted to enter the factory, and 300 people who had been in the middle and who had been in the middle divided into two parts," "in order for the intra-company joint and several meetings, 300 people who had been in the middle applied for changes in the indictment to "the entry of the outside people who attempted to enter the factory inside the factory from the front door to control the entry of the outside people who had attempted to enter the factory."

However, this is merely a partial revision to explain the details of the crime, and it is difficult to view it as a change in the facts charged that constitutes a change in the subject of adjudication, and it does not constitute a ground for ex officio destruction.

3. Determination

A. The crime of obstruction of the performance of duties under Article 136 of the Criminal Act is established only when the performance of duties by a public official is legitimate. Even if a public official commits assault or intimidation against a public official performing a duty lacking legality, it cannot be subject to the crime of obstruction of the performance of duties. In such a case, lawful performance of duties refers to a case where the act is not only within the abstract authority of a public official, but also meets the legal requirements and methods for specific performance of duties (see, e.g., Supreme Court Decision 2010Do13609, Jun. 13, 2013). The Act on the Performance of Duties by Police Officers prescribes “prevention of a crime” as one of the duties performed by a police officer under Article 2 subparag. 2, and Article 6 provides “A police officer intends to commit a crime before his or