Scotland proposes to join England and Wales in abolishing the rule against double jeopardy in some criminal matters. According to the story on the BBC site, the move appears to have been prompted by the acquittal, three years earlier, of a person suspected of being guilty of some terrible murders.
The Scottish Law Commission released a report on double jeopardy [PDF] at the end of last year, recommending that the law be changed to permit an acquittal to be set aside where the trial was "tainted." The Commission was unable to reach a conclusion as to whether an acquittal might be set aside on the basis of new evidence.
In England and Wales, Part 10 of the Criminal Justice Act 2003 permits the Court of Appeal to set aside an acquittal and order a retrial for certain serious offences (e.g. murder, kidnapping, a number of sexual offences) where there is "new and compelling evidence" and it is in the "interests of justice" to do so. (See also the BBC story at the time the law took effect.)
In Canada, of course, the rule against double jeopardy is located in section 11(h) of the Charter of Rights and Freedoms:
Any person charged with an offence has the right
h) if finally acquitted of the offence, not to be tried for it again and, if finally found guilty and punished for the offence, not to be tried or punished for it again;
Our criminal law does not prevent an acquittal from being appealed by the prosecution, as is the case in the United States.
