I haven't got much experience with jury trials. My reply was based on the Dutch system ;)
I've heard that a judge can find him guilty of murder/manslaughter, but the judge can decide not to let the murderer serve a sentence. Might be...
I believe you can still call your creatures 'vampires' and get away with it. Your vampires sound terrifying.. Maybe it will install some sense...
Separate names with a comma.