I am going to essay a WAG here, and caveat it as such:
I believe that such cases would not be appeals per se, but rather habeas corpuis petitions to re-examine the case based on the potential that evidence used to convict may have been tainted, and if successful would lead to vacating of the conviction and a de novo trial in which the presumption of innocence is back in place.
I seek confirmation or correction from Dopers at Law who would actually know whether this is accurate.
Strictly speaking that’s a civil matter rather than a criminal one. I don’t think it’s been changed. Basically the thinking isn’t that you’re innocent of defamation until proven guilty, as much as the person you’ve been said to have defamed is innocent until you can prove them guilty of whatever allegations you’ve made.
It is now, but there was still a criminal libel offence until last year.
Here the way that software license law is written, you must prove you have a license. So if say, microsoft accused me of license violation, I have to prove my innocence. But that’s one specific law and not an entire legal system.
Well, that’s a bit misleading.
If I sue you for defamation, the onus is on me to prove (a) that you published a statement about me, and (b) that the statement is defamatory (i.e. that it tends to lower me in the eyes of the community).
Once I show prove two things, you’re in trouble. You can defend yourself by arguing that I have not discharged the onus - I have not shown that you published the statement, or that I have not shown that it is defamatory.
Or you can raise other defences - e.g. that the statement was privileged, or was published on a privileged occasion, or that it is “justified” - meaning, yes, it may be defamatory in the sense that it will damage your reputation, but that’s OK, because it is true.
There’s no opening presumption that the statement is false. Truth or falsity is not an issue unless the defendant chooses to make it an issue, by relying on the defence of justification. If he chooses to raise the issue of truth as part of his defence, he has to prove truth. But there is nothing unusual in that; it’s generally true, in a civil case, that the onus of proof is on the defendant to establish whatever defence he relies upon.
This must obviously depend on the specifics of the law of the jurisdiction concerned and IANAAmericanL but, in general, you wouldn’t do this by way of a habeas corpus application. It’s generally a complete answer to a habeas corpus application to show that the applicant was convicted of a crime and sentenced to imprisonment and is held on foot of the sentencing order.
This would be by way of appeal, and whether the appeal is by way of a complete rehearing, with the benefit of the original presumption of innocence, or by some other procedure will depend both on the law and on the particular circumstances.
The most problematic case arises where the defendant has already exhausted all his appeals before the new evidence comes to light. In the Good Old Days in most common law countries his only recourse was a petition to the executive for some kind of clemency on the basis that his conviction could no longer be regarded as safe. However many (most?) common law countries have now adopted some kind of procedure whereby a case can be remitted to the courts when substantial new evidence emerges, to review the original conviction and order the conviction quashed, with or without a retrial.
The onus is likely to be on the applicant (i.e. the convicted person), but he doesn;’t necessarily have to prove, beyond all reasonable doubt, that he did not commit the crime concerned. The onus will be less burdensome and will focus not on whether he committed the crime, but on whether the verdict that he did can safely be relied upon, in the light of the new evidence.
From this WSJ article about Mexico’s system:
The longer article is an interesting read, and the film mentioned (Presunto Culpable - Presumed Guilty) is available free legally on YouTube and other sources (with English subs). It’s a rather stunning view of how the legal system works in an otherwise modern, western country.
I don’t think guilty until proven innocence was codified in Salem Village or in Spain during the Inquisition. Men and women tried to witchcraft in Mass. were required to enter a plea before the court could proceed.
I can’t speak for the other countries, but in Canada, the test for the admission of fresh evidence is a combination of due diligence and its likely effect on the verdict.
The due diligence aspect is simply that the convicted person has to show that this truly is fresh evidence - that he didn’t know about it at trial and could not reasonably have been expected to know about it. The hypothetical example would likely meet that test - a crooked cop would likely do everything he could to keep his habit of planting evidence a secret.
The second step of the test is to ask, “If this evidence had been led at trial, is it likely that it would have affected the outcome?” This phrasing of the test favours the accused: he doesn’t have to prove his innocence overall in the court of appeal, and he doesn’t have to argue that the fresh evidence is so compelling that it proves his innocence. All he needs to do is show that the fresh evidence is significant enough that it could reasonably have affected the outcome.
If both branches of the test are met, the appellate court will admit the fresh evidence. However, appellate courts aren’t there to re-try cases. Instead, it will then quash the conviction and order a new trial, with the fresh evidence available to the accused.
It will then be up to the Crown to determine if the fresh evidence is so compelling that it would not be appropriate to re-try the case. If the Crown concludes not, it would enter a stay. If the Crown concludes there is still sufficient evidence to support a trial, then the matter will proceed to trial with the fresh evidence. For instance, in this hypothetical, the Crown may conclude from its review of the case that the police officer did not in fact tamper with the evidence in this case, even though he appears to have done so in other cases; a question of credibility for the jury to determine.
More generally on appeals, the convicted accused does not have the benefit of the presumption of innocence. The court below has found that he was guilty, so the presumption has been rebutted by the Crown. On appeals, the task of the accused is to argue that there were sufficient errors made in the trial process that the conviction is unsafe. In some cases, the appellate court may accept that argument, allow the appeal, and order a new trial. In other cases, usually turning on pure questions of law, it may allow the appeal and enter an acquittal. However, those cases are rare, since most appeals involve some element of the appreciation of the evidence, which is not the task of the appellate courts, as outlined above.
Do you have any memory of the case law that says there has to be diligence? I’m not disagreeing, it seems like a fairly common sense rule. But I’d like to know it in a bit more detail.
[QUOTE=MichaelEMouse]
Do you have any memory of the case law that says there has to be diligence? I’m not disagreeing, it seems like a fairly common sense rule. But I’d like to know it in a bit more detail.
[/QUOTE]
Sure! The main SCC case is Palmer v. The Queen, [1980] 1 S.C.R. 759:
[QUOTE=McIntyre J for the Court]
Parliament has given the Court of Appeal a broad discretion in s. 610(1)(d). The overriding consideration must be in the words of the enactment “the interests of justice” and it would not serve the interests of justice to permit any witness by simply repudiating or changing his trial evidence to reopen trials at will to the general detriment of the administration of justice. Applications of this nature have been frequent and courts of appeal in various provinces have pronounced upon them. The following principles have emerged: (1) The evidence should generally not be admitted if, by due diligence, it could have been adduced at trial provided that this general principle will not be applied as strictly in a criminal case as in civil cases. (2) The evidence must be relevant in the sense that it bears upon a decisive or potentially decisive issue in the trial, (3) The evidence must be credible in the sense that it is reasonably capable of belief. (4) It must be such that if believed it could reasonably, when taken with the other evidence adduced at trial, be expected to have affected the result. The approach thus taken follows that of this Court in McMartin v. The Queen, [1964] S.C.R. 484.
[/QUOTE]
There’s been a lot of case-law on this issue over the years, but I think Palmer is still the main case.
(Note that I collapsed points (2), (3) and (4) in my earlier post, just to make it simpler to follow. Don’t do that if you’re arguing this issue in court 
)