In the beginning of the 5th book/ movie, Harry was charged for using underage magic in front of a muggle. Harry, in his defense, said that he had to use magic to fight Dementors. People laughed because they thought that a wizard of that age couldn't create a Patronus. Also, Dementors don't usually wander in muggle suburbs.

Why didn't court simply use Veritaserum (most powerful Truth Serum in existence) on Harry to know the truth? Wizengamot should have a stockpile of Veritaserum because it can be useful to it. Also, I don't think criminals can resist a Truth Serum, otherwise there's no point of their existence if we can't say with confidence that a subject under the influence of a Truth Serum is telling the truth.

  • Related, unsure if dupe: Veritaserum - objective or subjective? which is the dupe-target of Why didn't the Ministry use Veritaserum to question criminals? and Wizarding Court and Veritaserum (unsure if dupe, because admittedly Harry might not have known how to defend against it, hence justifying the Veritaserum's use)
    – Jenayah
    Aug 21, 2018 at 15:25
  • @Jenayah The second one is the most similar.
    – Alex
    Aug 21, 2018 at 15:28
  • 1
    Dumbledore could have suggested it in his defence--- but probably didn't want to ... what with Harry knowing the whereabouts of Sirius etc. ...
    – BMWurm
    Aug 21, 2018 at 15:29
  • 4
    @BMWurm actually, both sides have their reasons not to want to use Veritaserum. Remember, the Ministry was trying to shut away the "Voldemort is back, folks, it's true!" so-called ramblings Harry spread. Don't want to 1/ hear that well, it's actually true 2/ also, there really were Dementors
    – Jenayah
    Aug 21, 2018 at 15:34
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    @Jenayah is correct and could make a good answer out of the comment. Remember, Umbridge was the one that sent the Dementors in the first place, she and the Minister had no interest in actually hearing the truth since the truth was not what they were interested in sharing with the public
    – NKCampbell
    Aug 21, 2018 at 15:39

1 Answer 1


JK Rowling has explained that Veritaserum is not routinely used in court cases because it is "an unfair and unreliable tool to use at a trial" (bold text mine):

Q. Veritaserum plays a big part in finding out the truth from Mad-Eye Moody in book four. Why then is it not used for example in the trials mentioned in the same book? It would be much easier in solving problems like whether Sirius Black was guilty or not?

JKR : Veritaserum works best upon the unsuspecting, the vulnerable and those insufficiently skilled (in one way or another) to protect themselves against it. Barty Crouch had been attacked before the potion was given to him and was still very groggy, otherwise he could have employed a range of measures against the Potion - he might have sealed his own throat and faked a declaration of innocence, transformed the Potion into something else before it touched his lips, or employed Occlumency against its effects. In other words, just like every other kind of magic within the books, Veritaserum is not infallible. As some wizards can prevent themselves being affected, and others cannot, it is an unfair and unreliable tool to use at a trial.

Sirius might have volunteered to take the potion had he been given the chance, but he was never offered it. Mr. Crouch senior, power mad and increasingly unjust in the way he was treating suspects, threw him into Azkaban on the (admittedly rather convincing) testimony of many eyewitnesses. The sad fact is that even if Sirius had told the truth under the influence of the Potion, Mr. Crouch could still have insisted that he was using trickery to render himself immune to it.

While Harry is far less skilled of a Wizard than Barty Crouch Jr. or Sirius Black, it stands to reason that, because there is the possibility of fakery (especially with someone as powerful as Dumbledore on his side), the Wizengamot on principle does not administer Veritaserum to defendants.

And even if the Wizengamot could have considered Veritaserum for Harry, consider too that the Ministry does not want to encourage Harry's story that Voldemort is back. If he's given Veritaserum and starts repeating his story, that makes it harder for the Ministry to deny.

  • I think the last paragraph applies, they don't want to know. The other argument, unfair towards the defendant, doesn't apply, as Harry would want to prove that Voldemort is back. Aug 22, 2018 at 16:38
  • @QuestionAuthority I think the "unfair towards the defendant" argument may be a more general rule, rather than one that applies specifically to Harry. It's the same reason that polygraph tests aren't admissible as evidence in our modern courts. Even if you have someone who you are pretty sure doesn't know how to fool it, the fact that there exist people who do know how to fool it means that in general the courts don't allow it to be used on anyone. Aug 22, 2018 at 16:47

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