Even the most persistent crook deserves a fair trial

The conviction of Barry George for the murder of Jill Dando concludes (for now, at least) a story that might have come straight out of Hollywood. But it leaves in its wake a host of issues that merit further examination: the implications of celebrity in a modern world, the availability of guns, the fact that a man such as George was allowed to be in a position to be able to harm Jill Dando.

But there is one issue that is of immediate impact. We now know that George was a convicted sex offender and a dangerous man. But the jury did not know this when it came to consider his guilt. Prosecution barristers may not make use of previous convictions in all but the most limited of circumstances, no matter how relevant the crimes may be. In last month's Queen's Speech, the Government announced plans to change that rule. The Barry George case highlights both the pros and the cons.

Too many jurors are familiar with the awful feeling that a person they acquitted is revealed after the verdict to have a string of convictions. Since there is, by law, no real research into how juries consider their verdicts, we can only go by anecdotal evidence – although common sense suggests that on many occasions previous convictions would have been enough to tip the scales of justice against a defendant. However, to take an extreme and sometimes serial crime, just because someone has raped before, it does not hold that he has raped again – and therein lies the problem. It is a fundamental principle of our laws that trials are about what you have done, not who you are. The most vile criminal is no less deserving of a trial on the facts of the matter rather than insinuations based on their character.

Clearly, such previous convictions are not wholly irrelevant. The issue of character can matter – it is often a pivotal factor in determining guilt or innocence. We do not know what thoughts went through the mind of the one juror in the Barry George case who voted for his acquittal. Perhaps he or she felt the prosecution case was weak, as many observers seemed to think. But it is perfectly possible that George's character was the main stumbling block – that he seemed more of an eccentric than a psychotic killer.

It is understandable that the Government is proposing to do away with this rule – but wrong. Some guilty defendants may continue to escape justice. But better that than innocent ones are convicted. British justice has had enough black marks against it recently.