[7] Scots law requires corroboration; the evidence of one witness, however credible, is not sufficient to prove a charge against an accused or to establish any material or crucial fact.
[10] By the early 17th century, the standard practice of juries in Scotland was to return a finding of "fylet, culpable and convict" or "clene, innocent and acquit".
In 1728, in the trial of Carnegie of Finhaven for the murder of the Earl of Strathmore, the defence lawyer (Robert Dundas) persuaded a jury to reassert its ancient right of acquitting, of finding an accused "not guilty", in spite of the facts being proven.
If the jury brought in a "proven" verdict they would in effect constrain the judge to find Carnegie guilty of murder, for which the punishment was hanging.
To avert this outcome, the jury asserted what it believed to be their "ancient right" to judge the whole case and not just the facts, and brought in the verdict of "not guilty".
Legal academic Ian Willock argues that the 1728 case was "of great significance in calling a halt to a process of attrition which might have led to the total extinction of the criminal jury".
[15] Unsuccessful attempts to scrap the "not proven" verdict were made in Parliament by Donald Dewar in 1969, George Robertson in 1993 (prompted by the trial outcome in the murder of Amanda Duffy) and Lord Macauly of Bragar in 1995.
[17] In April 2023, the Scottish government published the Victims, Witnesses, and Justice Reform Bill which, if passed, will abolish the not proven verdict.
In general, the Scottish verdict has not been permanently adopted outside its home country, but it was sometimes used in colonial Canada, especially by some judges in southwestern Ontario[citation needed].
Its most famous use in the United States came when Senator Arlen Specter tried to vote "not proven" on the two articles of impeachment of Bill Clinton[20] (his votes were recorded as "not guilty"[3]) and when, at the O. J. Simpson murder case, various reformers, including Fred Goldman, Ron Goldman's father, pushed for a change to "not proven" because of what they felt was an incorrect presumption of innocence on the part of Simpson.