Could Avada Kedavra be used legally against werewolves in their transformed state?
Humans turn into werewolves only when bitten. There is no known cure, though recent developments in potion-making have to a great extent alleviated the worst symptoms.
Once a month, at the full moon, the otherwise sane and normal wizard or Muggle afflicted transforms into a murderous beast. Almost uniquely among fantastic creatures, the werewolf actively seeks humans in preference to any other kind of prey [...]
This classification [beast] refers, of course, to the werewolf in its transformed state. When there is no full moon, the werewolf is as harmless as any other human.
Fantastic Beasts and Where to Find Them - pages 41-42 - Scholastic - An A-Z of Fantastic Beasts
Werewolves are kind of a juxtaposition. They are human, but also beasts -- one of the most dangerous, murderous beasts, in fact, who actively seek out human prey.
‘Now ... those three curses – Avada Kedavra, Imperius and Cruciatus – are known as the Unforgivable Curses. The use of any one of them on a fellow human being is enough to earn a life sentence in Azkaban.' - Mad-Eye Moody
Goblet of Fire - page 192 - Bloomsbury - chapter 14, The Unforgivable Curses
For the entire moon cycle, less the day/days of the full moon, a werewolf is considered a human. During the full moon a werewolf is classified as a beast. If a witch or wizard was to use Avada Kedavra against a human while he/she is transformed into a werewolf, would that be considered legal? Or would the human aspects of the werewolf be enough to send a witch or wizard to Azkaban if he/she used Avada Kedavra and killed a werewolf?
I do not prefer an answer from the HP Wikia or the Wikipedia.