Dear Professor Snape,
Since you know a great deal about potions I thought that perhaps you would be able to answer a question I have about veritaserum. What are the restrictions concerning the use? Is it allowed to use it in hearings? If not, why? Wouldn’t it be a great way to make sure that the right people were convicted? When Voldemort disappeared the first time and people said that they had been imperiused, howcome The Ministry had such trouble sorting out the liars?
Dear Curious Hufflepuff,
Veritaserum is a dangerously potent potion. When mixed and administered correctly its results are beyond contestation. One must be careful when fighting the forces of evil not to resort to the same means as evil. To render so many persons unable to choose truth over lies, or indeed even to behave naturally, isn’t that different than Voldemort’s control.
Remember, just because you can do a thing, doesn’t mean you should.