1) You are frightened hearing about this. Perhaps it was in your neighborhood and you're worried about your house being robbed next.
2) Not likely. It sounds like you think ghosts were responsible.
3) The robbers held people hostage while they robbed the place, perhaps at gunpoint. It was terrifying for the people involved.
4) Not likely, because "horror" for me involved harm to humans (or living things) not theft. If they killed all the hostages, it would be horrifying, but no longer just a robbery.