Perfect Crime Designer

"Lin Que, you are under arrest." I'm just a librarian with a monthly salary of 3,200, how could I become a murder suspect? What's even more outrageous is—— The popular actress drowned in a secret room on the 28th floor. Her lungs were full of seawater, but the room was not touched by water. The police said it was "Poseidon demanding his life." I said, "This is not scientific... Wait, this is scientific." From that day on, I became a special consultant to the police. Every "impossible crime" was slapped in the face by my knowledge of physics. But I discovered a terrible fact: All the murderers call me "Teacher". All criminal modus operandi were inexplicably familiar to me. In the basement of my house, there are criminal plans written by me. Ten years ago, who was I? The "teacher" who designed the perfect crime... Is it me? If so, how do I catch myself?