Writing a forensic supernatural story, need advice
So I'm writing a story about what a college town thinks is an elusive serial killer is actually a killer ghost. The scene is essentially a young woman goes to use a pregnancy test and is cut to pieces while in the girls restroom, however, since the killer is from another plane of existence, based out of a portal network connected with bathroom stalls, there is no trace of entry or exit of an attacker as far as the world outside the bathroom is concerned. Upon finding this grisly scene, what are some observations and procedural steps the police and forensics team would do to attempt to make sense of this situation? I have a basic understanding of CSI but not in the sense of how something as enigmatic as this would play out in the real world. Any feedback would be greatly appreciated!!