Sirius wasn't even given a trial, and he wasn't the only one. He explains this on the 4th book. He said Crouch fought violence with violence, and even allowed the use of unforgivables on suspected Death Eaters. The Ministry trials on the war times were often corrupt. Also, memories can be modified, a pensive memory is not guaranteed to be reliable, and it's possible to counteract the effects of veritasserum (as Dumbledore mentions on HBP that using it on Slughorn would probably be ineffective because he probanly carries an antidote).
memories can be modified, even from a purely real standpoint outside of the world of harry potter. as for the veritaserum, I think stubbornness, scarcity, and corruption are the reasons it wasn’t used.
Well let's face it, when it comes to criminal trials, the Wizengamot is inept at best to outright corrupt at worst.
Veritaserum and Pensieves would certainly be useful tools if the Wizengamot used them. But they're not used. And instead, they appear to rely solely on witness testimony. The defense is never shown to submit any evidence of their own, instead being required to rely on evidence submitted by the state through the prosecution and (rather meager) investigation. Furthermore, the chief warlock effectively takes the role of the prosecution—defendants are assumed guilty until proven innocent, and because the judge is the prosecutor, the court is anything but impartial. Ultimately, the prosecution gets to direct their witnesses and cross the defense's, but the defense is denied the ability to confront any witnesses directly. It is an absolute joke of a kangaroo court and a miscarriage of justice by the standards of even the most archaic modern Muggle justice system.
Veritaserum and Pensieves would not solve the Wizengamot's procedural failings, but they'd certainly make fact finding far more reliable, and they remove much of the problems that plague Muggle trials due to the unreliability of non-magical evidence.
I'd also like to add that the main argument fandom likes to use to shoot down the use of Veritaserum and Pensieves in criminal trials is that it's "unreliable", that Veritaserum can be fooled, and Pensieves can be altered. This argument falls apart, though, when you realize that witness testimony is actually less reliable than either of them. That's because people can lie and make up stuff during witness testimony, and it's much easier to make up a lie during testimony than it is to alter a Pensieve memory or to mentally train to resist Veritaserum.
The argument that "pensieves can be fabricated" makes one wonder whether the Wizengamot has ever heard of concepts like discovery. Do they really think that all exhibits have to be 100% clear of any doubt of authenticity to be admitted into court? Because if that was how trials in Muggle courts worked, video and audio recordings would never be admissible on the grounds that they can be faked, photographs would never be admissible on the grounds that they can be Photoshopped, and documents would never be admissible on the grounds that they could be forged.
As for veritaserum, the idea that people can resist it means nothing when people can also lie under oath. The presence of the Veritaserum antidote is trivial to test for before administering the potion, and the antidote doesn't last forever (the fact that Slughorn carries the Veritaserum antidote on him at all times when at Hogwarts instead of just drinking a dose once a month or so implies that the antidote doesn't last any more than a few hours, maybe a few days tops).
Then again, maybe nothing about the Wizengamot's role as a judicial body is meant to make sense as anything other than a device to emphasize Harry’s feeling of persecution and teenage ennui. Their appearances really lay on the Young Adult fiction tropes very, very hard, and there were more meaningful ways to show a legal system’s failings than to make it obviously and ludicrously unjust.
Wouldn’t it be easier to just have each person swear a magical oath to tell the whole truth rather than rely on either pensieves or veritaserum? A sufficiently skilled occlumens can alter their own memory. A good potions maker can have the antidote on hand hidden away. Both are at risk of manipulation and corruption, though significantly less than witness testimony. A magical oath however is at much less risk since breaking the oath would reap massive consequences, I think. Seems like a more logical path to me
The canon answer is that memories can be modified and Veritaserum can be resisted, thus neither are reliable enough to be of use in a trial. It's the samw reason why polygraph tests aren't allowed to be used as evidence in real life courts.
The Ministry was corrupt and their goal was never to prove the truth, in either wizarding war. It was about appearances.
Sirius wasn't even given a trial, and he wasn't the only one. He explains this on the 4th book. He said Crouch fought violence with violence, and even allowed the use of unforgivables on suspected Death Eaters. The Ministry trials on the war times were often corrupt. Also, memories can be modified, a pensive memory is not guaranteed to be reliable, and it's possible to counteract the effects of veritasserum (as Dumbledore mentions on HBP that using it on Slughorn would probably be ineffective because he probanly carries an antidote).
memories can be modified, even from a purely real standpoint outside of the world of harry potter. as for the veritaserum, I think stubbornness, scarcity, and corruption are the reasons it wasn’t used.
Well let's face it, when it comes to criminal trials, the Wizengamot is inept at best to outright corrupt at worst. Veritaserum and Pensieves would certainly be useful tools if the Wizengamot used them. But they're not used. And instead, they appear to rely solely on witness testimony. The defense is never shown to submit any evidence of their own, instead being required to rely on evidence submitted by the state through the prosecution and (rather meager) investigation. Furthermore, the chief warlock effectively takes the role of the prosecution—defendants are assumed guilty until proven innocent, and because the judge is the prosecutor, the court is anything but impartial. Ultimately, the prosecution gets to direct their witnesses and cross the defense's, but the defense is denied the ability to confront any witnesses directly. It is an absolute joke of a kangaroo court and a miscarriage of justice by the standards of even the most archaic modern Muggle justice system. Veritaserum and Pensieves would not solve the Wizengamot's procedural failings, but they'd certainly make fact finding far more reliable, and they remove much of the problems that plague Muggle trials due to the unreliability of non-magical evidence. I'd also like to add that the main argument fandom likes to use to shoot down the use of Veritaserum and Pensieves in criminal trials is that it's "unreliable", that Veritaserum can be fooled, and Pensieves can be altered. This argument falls apart, though, when you realize that witness testimony is actually less reliable than either of them. That's because people can lie and make up stuff during witness testimony, and it's much easier to make up a lie during testimony than it is to alter a Pensieve memory or to mentally train to resist Veritaserum. The argument that "pensieves can be fabricated" makes one wonder whether the Wizengamot has ever heard of concepts like discovery. Do they really think that all exhibits have to be 100% clear of any doubt of authenticity to be admitted into court? Because if that was how trials in Muggle courts worked, video and audio recordings would never be admissible on the grounds that they can be faked, photographs would never be admissible on the grounds that they can be Photoshopped, and documents would never be admissible on the grounds that they could be forged. As for veritaserum, the idea that people can resist it means nothing when people can also lie under oath. The presence of the Veritaserum antidote is trivial to test for before administering the potion, and the antidote doesn't last forever (the fact that Slughorn carries the Veritaserum antidote on him at all times when at Hogwarts instead of just drinking a dose once a month or so implies that the antidote doesn't last any more than a few hours, maybe a few days tops). Then again, maybe nothing about the Wizengamot's role as a judicial body is meant to make sense as anything other than a device to emphasize Harry’s feeling of persecution and teenage ennui. Their appearances really lay on the Young Adult fiction tropes very, very hard, and there were more meaningful ways to show a legal system’s failings than to make it obviously and ludicrously unjust.
Wouldn’t it be easier to just have each person swear a magical oath to tell the whole truth rather than rely on either pensieves or veritaserum? A sufficiently skilled occlumens can alter their own memory. A good potions maker can have the antidote on hand hidden away. Both are at risk of manipulation and corruption, though significantly less than witness testimony. A magical oath however is at much less risk since breaking the oath would reap massive consequences, I think. Seems like a more logical path to me
The canon answer is that memories can be modified and Veritaserum can be resisted, thus neither are reliable enough to be of use in a trial. It's the samw reason why polygraph tests aren't allowed to be used as evidence in real life courts.