The aim is justice, yes? The...stranger things you hunt, like plague, that requires more magic than simple legal actions. But for the rest...

[Alucard shakes his head, as if aware of how dumb this sounds.]

Persecute within the existing systems by being among them day in and out then. Prevent a so-called witch's death by looking at the legal dispute over land first and arguing in front of magistrates. Then the act of justice is a daily occurrence for most. That saves more lives.