Killing someone can be justifiable in some circumstances, case by case basis. But killing someone for reason A can be wrong even if there's an unknown reason B that makes this person deserve death.
So if you kill someone because you think they're committing witchcraft and you think that makes it justifiable, you're wrong. Even if you find out 5 days later this person tortured your mum to death, you were wrong to kill this person for the reason you did.
In any case, is it ever justified to burn someone to death? I don't believe it is ever justified to cause pain for no other reason than to make yourself feel good, which is the idea of long drawn out deaths.
So if you kill someone because you think they're committing witchcraft and you think that makes it justifiable, you're wrong. Even if you find out 5 days later this person tortured your mum to death, you were wrong to kill this person for the reason you did.
In any case, is it ever justified to burn someone to death? I don't believe it is ever justified to cause pain for no other reason than to make yourself feel good, which is the idea of long drawn out deaths.