It is hard to think of a more obvious case than the death of Surjit Singh Chhokar for using Scotland's new double jeopardy rules to prosecute individuals previously acquitted.
That is not to prejudge the outcome of any retrial of Ronnie Coulter, Andrew Coulter or David Montgomery. The three men were previously brought to the High Court in 1999 and 2000 to face charges that they murdered the Sikh waiter in North Lanarkshire 15 years ago.
But these trials were unsatisfactory, damaging the reputation of the Scottish legal system as first Ronnie Coulter was acquitted in 1999 after blaming his nephew Andrew and Mr Montgomery, only for these two men to accuse the senior Mr Coulter and walk free in 2000. As subsequent inquiries pointed out, the Crown Office had set the conditions for the dismaying outcome by failing to try all three together.
The case led to soul searching within the justice system, including a finding that it had been hampered by institutional racism. In particular, the way Mr Chhokar's family, including his ageing parents, were dealt with by the authorities was culturally insensitive and inept. Their solicitor Aamer Anwar says the family will only ever be at peace when there is justice. Mr Chhokar's mother and father, in failing health, have always kept their dignity during the long wait for answers.
Now, perhaps, they will have answers as Lord Advocate Frank Mulholland, QC is requesting that the High Court set aside the previous acquittals and that the three men be prosecuted again. Overturning the double jeopardy laws that protected someone from being tried again for the same offence was always a change in need of careful monitoring. When it was introduced it was suggested the process would and should not be overused. That has proved to be the case and this is only the second application for a retrial since that law was changed: Angus Sinclair will stand trial again for the World's End Murders after Lord Carloway last month authorised the Crown to bring a new prosecution.
The bar for setting aside previous acquittals should remain high, and the High Court will determine whether it has been reached in the Chhokar case.
We should be clear that the principle of avoiding double jeopardy remains an important one. For hundreds of years, Scots law protected those acquitted of a crime from harassment by the state by ensuring they could not be tried again.
But in the process this led to injustices in cases where an accused later admitted the crime knowing they could never be retried or incases where compelling new evidence became available, for example.
The case of Mr Chhokar is a troubling example. The case against those accused of killing him was never properly tested. Those men remain innocent until proven guilty, in keeping with that vital principle in law.
The issue is not necessarily that justice has not been done. But it certainly has not been seen to be done, and that is why a retrial would be welcome.