How long should a prison sentence be for a particular crime? People call for consistency and this call is often backed up by politicians. It’s an easy and popular bandwagon to get on.

The argument may be reinforced by the figures produced by The Sunday Times Scotland last week, which showed that over the period 2003 to 2007 there have been 520 successful appeals against sentences handed down in our High Courts and 40 convictions have been overturned. Astonishingly, almost a fifth of the successful appeals concerned the sentences imposed by one judge, the former Labour lord advocate Lord Hardie, whose sentences were successfully challenged in 84 cases, and in two the conviction was quashed.

These appeals all cost a deal of public money, which is one cause for complaint. This is reasonable enough: it’s a bad thing if a judge is making mistakes. On the other hand, one might argue that the decisions of the appeal judges show that our legal system is actually in rather good health. Politicians have, of course, a role to play. It is parliament which makes laws and parliament can, if it chooses, impose minimum sentences for certain crimes and mandatory ones for others. Few would argue that a mandatory life sentence for those convicted of murder is not appropriate. There is frequently a public demand that life should mean life.

It’s only comparatively recently that, in response to public disquiet over the nature of a life sentence, judges have taken to stipulating a minimum number of years to be served in prison before release on licence may be considered. Our criminal justice system recognises that each case is individual and that punishment should be tailored as such. This is not something that politicians are qualified to do and it is one reason why they should not legislate for mandatory sentences, with the exception of declaring a minimum sentence for particular crimes.

Those who would like to see the freedom of judges restricted often advance the argument that, being Establishment Figures, they are out of touch with ordinary citizens and even with the nature of criminal activity; that they may know the law, but don’t understand the victims of crime and can’t empathise with them. For the most part, this is manifest nonsense. Many years’ experience in the criminal courts gives judges a better understanding of the dark side of society than most of us have, a better understanding indeed than most politicians can boast of. Unlike the average law-abiding citizen, judges see the worst of our society day in and day out. And they pass sentence accordingly. Far from being removed from harsh reality, they are brought face-to-face with it.

Judicial freedom from political influence is an essential element in a free society. Without such freedom there is the danger that cases will be judged not on their merits, but in accordance with what seems politically expedient. Of course politicians, acting through parliament, may make laws and determine what is illegal, but they are not competent enough to interfere with the application of the laws they have made. Moreover, as many recent examples of Westminster legislation demonstrate, they don’t always understand the implications of the laws they have passed or how a particular piece of legislation may run counter to natural justice. Interpretation of what is law and of what is justice is properly, in a free society, the task of judges, not politicians. The only occasions a politician should have a role in a criminal trial are if he appears in the witness-box or the dock.

Politicians have assumed a role in connection with prison sentences, devising policies about early release. This has irritated both the public and some judges. Sheriff Drummond of Selkirkshire recently complained that a policy of early release was making a mockery of the sentences he passed. He had a fair point, though doubtless some of his colleagues take the likelihood of early release into account when imposing a term of imprisonment.

There remains, however, a real objection: that the decision to release prisoners when they have served only a short part of their sentence is more often made in consideration of prison conditions and overcrowding than with reference to the nature and gravity of the crime that has resulted in the imposition of a prison sentence. This is an example of what happens when politicians interfere with the judicial process.

The independence of the judiciary should be a given in any democracy. Of course judges make mistakes sometimes, just as we all do. But in our system there is a means of correcting such mistakes, and this is done by the judges who consider appeals against conviction or sentence. They do it in the light of the law as it is to be interpreted, and also in the light of natural justice. More often than not they get it right. In the end, of course, all lay opinion on such matters will be informed by personal attitudes. For my part, I would rather trust a Scottish judge than a Scottish politician any, and every, day of the week.

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