FINDING proof beyond reasonable doubt is a burden placed upon the prosecution in the quest for justice.

When a crime involves just two individuals, one of whom ends up dead, it is impossible to know who did what to whom and for what reason.

Nobody really knows what happened and even when the crime is witnessed by more people, what they see is open to interpretation and misinterpretation. The defence and the prosecution rely on hearsay, the subjective reports of witnesses who, after all, are human beings with prejudices, frailties and failings.

Quite often there is no justice at all. The jury of 12 men and women is simply swayed by whichever counsel puts forward the best case, whichever advocate is the best presenter and the most convincing performer.

And history shows there have been countless miscarriages of justice.

The Guildford Four - Patrick Armstrong, Carole Richardson, Paul Hill and Gerard Conlon - were convicted in 1975 and sentenced to life imprisonment for the 1974 Surrey pub bombings which killed seven people.

A years-long campaign for justice finally cast doubt on the evidence, particularly confessions which had helped to convict the four but which they always maintained had been extracted by force. There were more problems with the police officers' notes and in 1989 the Guildford Four were freed.

Similarly the Birmingham Six - Richard McIlkenny, Patrick Hill, William Power, John Walker, Gerard Hunter and Hugh Callaghan - were jailed for life in 1975 for the 1974 bombing of the city's Mulberry Bush and Tavern in the Town pubs in which 21 people died.

It was an act of barbarism which caused a national outcry and put unbelievable pressure on the police to bring someone to justice. The six were convicted despite their claims of innocence.

It wasn't until 1991 that they were set free when fresh evidence made their convictions unsafe.

The Bridgewater Three - Vincent and Michael Hickey and James Robinson - were sentenced to life in 1979 for the killing of 13-year-old Midlands paperboy Carl Bridgewater. Again there were problems with the trial and a confession made by a fourth man.

The men were released on appeal 18 years later when their trial was deemed fundamentally flawed by the High Court.

Stefan Kiszko lost 16 years of his life after being convicted in 1976 of the murder of schoolgirl Lesley Molseed in Rochdale. Three appeal judges ruled his conviction unsafe and unsatisfactory after hearing scientific evidence that positively ruled him out as the killer, new evidence that was unavailable at the time of his trial.

New evidence rightly makes such convictions unsafe and frees the accused. But, to avoid double standards, surely the same principles should apply to those people who were wrongly acquitted.

But, because of an ancient law, a different set of standards applies.

Labourer Billy Dunlop last month confessed to a heinous crime yet will not pay the price unless that ancient law is changed. Dunlop, formerly of Flodden Way, Billingham, has twice walked free from court after juries failed to convict him of the murder of Billingham pizza delivery girl Julie Hogg, a crime he denied at the time.

Last month he confessed to the crime and is now serving a six-year sentence for perjury, for the lies he told during both trials.

Dunlop's confession sent shockwaves through the legal system and added fuel to the campaign by Julie's mother Ann Ming to bring him to trial.

Julie vanished from her home on November 16, 1989, and despite an extensive police hunt and week-long search of her home her body was not found. It was Mrs Ming who made the gruesome discovery three months later when police returned the keys of the property to her. She found Julie's mutilated body stuffed behind the bath panel; she had been sexually assaulted.

Dunlop's confession to a prison officer, while serving a sentence for a serious assault on his ex-girlfriend and her lover, raised hopes that he would finally be brought to book.

But the double jeopardy rule, which evolved to protect the public against malicious and incompetent prosecution, hit with full force.

To those in favour of it, the rule remains an important democratic safeguard against autocratic governments. They say that if the police know they can always go back there is no incentive to them to get the evidence right in the first instance.

It's a principle that has existed for 1,000 years and has been adopted by legal systems across the world. It has stood the test of time. So why change it, ask its supporters.

The Criminal Procedure and Investigation Act 1996 does remove the bar of double jeopardy if the trial verdict is considered "tainted" by an "administration of justice". A conviction for perjury seems to be such an administration of justice. But Crown prosecutors now say this only applies to jury tampering or if a key witness commits perjury, not the defendant.

So Mrs Ming, of Norton, near Stockton, takes her fight for justice to the Home Secretary Jack Straw today demanding that he take action to change a law which is unjust and outdated.

The foundations that have supported the ancient law of double jeopardy are under attack and appear to be crumbling fast.

A high-powered committee of MPs has also called for the repeal of the law and wants it to be done retrospectively so Dunlop can be tried.

The Law Commission has been asked to consider the issue and is expected to come to the same conclusion some time this year.

Advisor to Home Secretary Jack Straw, Lord Mackenzie of Framwellgate, is backing calls for a change in the law. He has told The Northern Echo: "I felt strongly about this in 1997 and feel equally strongly now. If the law is going to be held in high regard by the public it must be even handed.

"Provided there are proper safeguards, a miscarriage must be capable of being put right whether it be a wrongful conviction or wrongful acquittal."

Barrister Alisdair Gillespie, who lecturers in criminal justice at the Centre for Police Research and Education School of Social Sciences at the University of Teesside, believes the law will go.

"There is a big argument for a change in the law, though it's going to be controversial," he says.

"But it can't be a free for all. It should only be for serious crimes such as rape, murder and manslaughter, or perhaps gangland violence where there has been witness intimidation. Otherwise there is a risk the police may use it to keep trying to get a conviction."

But there is a catch. The Billy Dunlop case has been the catalyst for a change long overdue but unfortunately for the family of Julie Hogg he is still unlikely to get his just deserts.

"The Law Commission will produce a draft statute, probably in the next session of Parliament. There will be a crime and disorder bill which will abolish double jeopardy.

"But I don't think it will be back-dated because article seven of the European Convention on Human Rights would prevent that.

"So unfortunately it won't be retrospective which means that the victim's family will have to live with the fact that the self confessed villain has not been punished.