The Scottish justice system has a unique twist to the conundrum of the guilt or innocence of an accused. Jurors have a third option, to find the case "not proven".

Essentially this means that the court believes that the accused is most likely guilty but that the prosecution has not proved this beyond reasonable doubt. The accused leaves the dock a free person but not with the supposition of innocence contained in a "not guilty" verdict. Instead, moral absolution is withheld and there remains the implicatory taint that, were the prosecution just a tad more competent, the accused probably would be viewing the world through a set of prison bars.

There are two celebrity trials taking place at opposite ends of the world, where the prosecution is at present closing its case and no doubt fervently wishes that the Scottish system operated in their jurisdiction. The first is the trial in Los Angeles of the singer Michael Jackson on charges of child molestation and conspiracy, including kidnapping, extortion and false imprisonment. The other is in Durban, where businessman Schabir Shaik faces corruption charges arising out of the alleged solicitation of bribes during the arms procurement process.

In the Jackson case, the patent fragility of the conspiracy charges have led to Jackson's defence claiming that the district attorney's office is on a personal vendetta against the singer. In the Shaik case, the prosecution faces similar accusations that it is engaged in a political vendetta, with Shaik this week claiming on radio that the prosecutor is a "pawn in a political fiasco".

The Jackson case is complicated by the fact that the district attorney failed 11 years ago to win a conviction on similar molestation charges, when the singer reached an out-of-court settlement with his accuser. The prosecution is now trying to show that Jackson is a classic paedophiliac predator, with the one piece of convincing bolstering evidence - a 1994 conviction - sadly missing.

The Shaik case is complicated by the fact that the man who is closely linked to the same alleged offences, Deputy President Jacob Zuma, has not been charged, in spite of statements by the prosecuting authority that there was prima facie evidence of corruption against Zuma. The prosecution is trying to prove that Shaik solicited bribes in conjunction or on behalf of Zuma, yet the one thing that would credibly bolster such claims - Zuma in the dock as a co-accused - has not happened.

Eventual court acquittals of Jackson and Shaik will hardly matter. It will take scintillating defences to dissuade the public that, at best, the bulk of the charges against these men are - in Scottish parlance - "not proven?br> Similarly with Zuma, the ghost defendant.

Some might have sympathy for Zuma. He has not been charged - although he may yet be, depending on the verdict against Shaik - yet in terms of his political future it is as if he was. Given the calumnies against his name and secure in his innocence, Zuma might well have preferred to have endured the agony of the trial, certain of acquittal at the end.

The issue, however, is not judicial guilt or innocence. Zuma is a public figure, the putative next president of South Africa. An ironclad conviction in a court of law has never been the chief criterion of reputation and in most democratic countries -with the obvious exception of Italy - prima facie evidence of corruption or poor moral judgement will suffice to end a political career.

Among the uncontested evidence from the Shaik trial is the degree to which Zuma willingly entered into a financially dependent relationship with a businessman seeking to secure multi-billion rand state contracts. One could argue that to do so, Zuma is either as crooked as a hairpin or, at the most benign interpretation, so exceedingly naive as to verge on the stupid.

Either interpretation should preclude him from the presidency.

With acknowledgements to William Saunderson-Meyer and The Natal Witness.