The Scott Watson case should concern all New Zealanders, because it takes the standard of evidence needed to convict a citizen a step lower. This means that future accusations based more on supposition than hard fact have a greater chance of sticking, and even more people are likely to be imprisoned for crimes they didn’t commit.

The attendant difficulties go beyond people being unfairly jailed, which is bad enough – we are also likely to end up with an increasing number of cases in danger of splitting at the seams at a later date when solid evidence does emerge. Once one comes apart, many will in its wake, and will result in big claims for compensation and widespread failure of confidence in the justice system.

To take the Watson Case back to a few indisputable facts; two young people went missing on New Year’s Eve. They were last seen with a person since known as the "mystery man," and left a water taxi to stay on his boat, described as a two masted ketch by the driver who dropped them off.

It is not known that the mystery man, whoever he was, murdered them. It is not known that the guy was a "lone sailor." It is not known that they were actually murdered. Many things can happen at sea.

So at the very core of this case there is a supposition of murder, which repetition has made a truth. For there to be a murder, there has to be a murderer, and one must assume that Scott Watson first attracted police attention by having his boat moored in the broad general direction of where Guy Wallace said he dropped the children at a ketch.

He was alone on his boat, but the people who shared his mooring all vouched for the fact that he returned home alone in the early hours of the morning.

The "lone sailor" became another fact. There is absolutely no fundamental reason to suppose that the children were dropped off at a boat containing a lone sailor.

In a case based on circumstantial evidence, especially one lacking bodies, you would expect some strong links to be established between the deceased and the accused - a background of hatred, a big insurance pay-out, romantic jealousy, or conflict. Either that, or a sound, recorded history which suggests that the accused is a person highly likely to murder strangers, and in the position to do so. Scott Watson does have a history of petty crime, but no history at all of violence toward women. And there is nothing beyond location linking him to the two children.

Of the people who appeared in court to denounce Scott Watson as a person who might murder a woman, only two reported a conversation including a third person, and they were a husband and wife with the third person being each other. Normally evidence like this, with one person recounting what another person allegedly said without the support of others, is called hearsay, and discounted. Furthermore, in the period leading up to his arrest, the police themselves left Scott Watson to stay with his girlfriend for about three weeks, which they surely would not have done if they’d believed he was seriously dangerous.

In contrast to this, ketch sightings, which did follow a particular course out past Pelorous Sound, and were made by more than one person in many cases, were dismissed as mistakes. This includes the original people on the water taxi, all of whom agreed that the children were dropped at a ketch.

So, at the heart of this case we have a supposed double murder with no bodies, a supposed lone yachtsman, and a supposed desire for sex in a person without a history of that sort of crime, as the motivation.

If you remember that these premises are suppositions, not solid facts, then the weakness of the remaining evidence becomes apparent.

A man paints his boat to disguise it, and not only stays in the same town, he also goes to the police station of his own volition and states exactly where it was on the night in question. Boats are far less easy to disguise than cars, especially a boat as individual as Blade, but you couldn’t even do this with a Toyota Corolla. If you painted your car and stayed in the same place, people wouldn’t say, "That can’t be Fred, because the car’s a different colour."

The claimed cleaning of the boat to get rid of evidence is especially eerie when seen in this light. Two people have gone missing, and we don’t know exactly what happened to them, but we suppose they’ve been murdered. A man, who is unknown to them, has a boat which contains no evidence of either them or of a violent struggle, so we suppose he must have killed them and cleaned up afterward. This is a supposition built on a supposition, without a single plank of established fact supporting it.

Two hairs in a location may mean many things, but they do not automatically mean that a murder has taken place there, especially when we aren’t even certain there has been a murder. I’m sure there are pieces of my hair all over the town I live in, as people shed hair all the time. Some will be in places I’ve never been through secondary transference. A couple of hairs, for example, might fall out on the bus, I get off the bus and someone else takes my seat. He goes home, has a shower and now my two hairs are in his laundry basket, or his shower cubicle. He’d better watch out if I suddenly go missing, and am last seen in his suburb.

The only two witnesses in this case who have actively confirmed that a murder has taken place have been the two prison witnesses. Everyone else, for both the prosecution and the defence, have been participants in an expensive game of Cluedo. Who was where, at what time, and so on. How likely is it that a man, who was not heard admitting to murder over the course of five months of phone tapping, would suddenly confide in men like these two? These are not men who happened to be in jail because of one rash action, they both have a long history involving courts, policemen and prisons.

According to John Rowan, QC, in The NZ Law Journal, Dec 2000, "While jurors have varying degrees of life experience to assist them in assessing whether people are telling the truth or not, they have little or no knowledge of the strange, symbiotic relationship that can develop between informers and the police person who runs them."

In this case, one cannot overlook the importance of these men in the trial. They gave the only graphic confirmation that the two children were actually murdered. As is shown elsewhere on the site, one of these men has since recanted, or at least attempted to. For the reason I have just stated, this should be taken seriously as grounds for a retrial.

The big difficulty faced by Scott Watson and his lawyers now is this; a conviction gained by slight evidence can be very hard to disprove. There is a danger that nothing within the case can easily be considered "important enough" by itself to overturn the decision through the truth of it being revealed.

Prison witnesses recant, they were only a minor part of the case anyway.

The rules concerning forensic samples, identification, etc, change, the cry will no doubt be, well not much importance was placed on them anyway.

We already have one identification witness recanting, saying, after having seen an actual photo of Scott Watson, that he was not the man she served in the bar, who was allegedly also the man who accompanied the children on the boat. It’s quite possible that little importance will be placed on that as well.

It seems likely that those who could have something to offer in allowing the truth to come out, may be further intimidated by the nature of the case against Watson. The same net could be cast in their direction, along with the problems that may be unleashed by upsetting real criminals.

But the longer cases like this pile up, the worse it can only become for the legal system, and hence the democracy of this country.