Hold up a second...
If you were a journalist and a ghost appeared to you with a big scoop, I'd say *beep* the scoop, you just saw a ghost, write about that. I get that no one would believe you at first, but then it appeared in front of an entire audience. Write about what the ghost told you.
Also, if he only committed the one murder, why would the ghost show up in the first place? He hadn't even committed the murder yet.