system
Given the following post, respond as if you're commenting on Reddit:
human
[Buffy / General Vampire Fiction ] Is it illegal to kill a vampire?

 So as vampires obviously have no mention under the law personally I can see the act of killing a vampire going two ways.

1. The vampire in interpreted as being a human being with a medical condition. As humans are turned into vampires this would make sense and despite their heart no longer beating they are still behaving as if they are alive so could be interpreted as being alive the same way someone on a heart bypass is.
2. Vampires are not seen as alive and therefore killing them is seen as Desecration of a Corpse. As you would still be harming the corpse in order to kill the vampire.

Obviously, I mean if it wasn't in self-defence as in if the person was a Vampire Hunter not just some person whose about to be eaten.
gpt
I think the law would definitely frown on the extrajudicial killing of anything that could potentially walk into a courtroom and claim to be a person.

The real trick, of course, would be proving that anyone had been killed when the only remains are a surprisingly small pile of dust. Lack of a body isn't an automatic get out of jail free card, but it is a huge obstacle to a murder case.

Plus, the most likely "witnesses" would be other vampires. Good luck getting them to swear on a Bible.