The office was locked from the inside, and the author was hanged outside the window on the 14th floor. How did the murderer complete the unsolved case in the secret room?

How did the murderer complete the unsolved case in the secret room when the office was locked from the inside? This was a rather interesting plot. Here are some possible scenarios I can provide: The murderer used the window or other opening to enter the office and used tools or ropes. During this process, he could observe the situation in the office and look for clues and evidence, such as any suspicious items in the office. The murderer could have set up traps and puzzles in the office to test the employees 'reasoning ability and logical thinking. He might place traps on walls, ceiling, or other surfaces for employees to solve riddles to find hidden clues or evidence. 3. The murderer could use any object in the office as a weapon such as a knife or a gun to threaten the employees or test their reaction ability. He could also deliberately create some accidents such as breaking cups or computers to test the employee's adaptability and psychological quality. The murderer may be a team. They work together to complete the murder mission. One of them could be a planner or a killer, the other a psychologist or a detective. Together, they search for clues and evidence and use the details in the office to create accidents and puzzles. The above are just some possible plots. The specific plot depends on the imagination and creativity of the author.