I Ask You to Investigate the Case, How Do You Start a Forum?

The woman went to attend a class reunion two days ago, but was quartered. Who is the murderer? Zhao Munan's method of opening a forum. The murderer is actually him! The couple traveled abroad, but the wife mysteriously disappeared, neither alive nor dead. Zhao Munan's method of opening a forum... Zhao Munan was a Taoist priest in his previous life, but he became a policeman in this life. He discovered that the Taoist knowledge he had learned could actually be turned into magic in this world. So, he used magic to start his investigative life in another world. What to do if there are no witnesses or physical evidence? It doesn't matter, I'll just start the forum and let the deceased tell me who the murderer is!