
In modern day USA where most people don't believe in magic, a mysteriously burned body has been found by with Character A's finger prints on it in the parking lot outside a country club where a wedding took place. In reality, the body was burned magically by Character B (and the investigators don't know magic is possible), and Character A was trying to put out the flames and save the victim's life. Then Character B kidnaps Character A. Both Character A and B were wedding guests, and while the authorities questioned Character B because he was related to the victim, they don't suspect him. The authorities will declare Character A missing.
Ultimately, the authorities need to declare Character A either a "person of interest" or "suspect". I googled "person of interest or suspect" and "person of interest suspect difference" and found that persons of interest are just people who the police want to talk to for their investigation, and while persons of interest can become suspects, this isn't always the case.
1) Would the fingerprints be enough for the police to declare Character A a suspect or would they just call her a person of interest?
2) Would a suspect/person of interest in an investigation of a mysteriously burned body of a random citizen (not a politician or anyone high profile) be important enough to broadcast all over the news, even in a different state, especially considering that the suspect/person of interest is missing?
Sorry if I tagged or formatted this wrong. Just found this community. (It's very awesome. You guys are amazing.) Also, I'm typing this out on my iPod, so hopefully I caught all the typos, but if I didn't, heh, sorry.

Setting: secondary world deiselpunk
I know it's secondary world and I can handwave all I want, but if I can get a true to life as possible, it always adds credibility to the story.
My characters are executing a train robbery, and stealing the actual cars. I want my characters to uncouple the last 8 or so train cars of a train, while it's moving. I'm not even sure if this is possible - I'm sure it would be dangerous, but that's beside the point. I'm thinking to say it's a janney coupler, since those would have been in use in the real world in that era, but I've googled variations of coupling and uncoupling janney couplers, aar couplers, etc, and there's a number of videos of them coupling and uncoupling, but not from an angle where I can actually see how it works to describe it, let alone figure out if it could be done on a moving train. There seems to be a pin involved, but the videos move too fast to see it in action.
If it's not possible, I can invent an imaginary type of coupler that makes it possible, just want to do due diligence first.