The anonymous jury member said that instead of being found guilty of murder, Jon Venables and Robert Thompson should have been found "guilty as frightened and largely unaware children who made a terrible mistake and who are now in urgent need of psychiatric and social help".

In a letter published in The Guardian, the juror said: "The defendants were children - young, ill-educated, of a social background which, I suspect, had included little direction or support; caught up in circumstances which they only partly comprehended and within which they made appalling choices."

'Was justice really served?'

The juror criticised the decision not to allow the boys any psychiatric help until after the trial.

The complicated issue of whether they understood what they had done was reduced to a yes or no answer from a psychiatrist "bullied" into giving a response, said the juror.

Sir David Ramsbotham was criticised for calling for killers to be freed

The jury was also never told that the boys were persistent truants who were unlikely to have picked up lessons on morality at school, the letter added.

The juror contends that the children plainly did not understand most of what was going on in court and were distressed by the parts they did grasp.

The juror wrote: "I have no doubt that they did commit a dreadful act and I have the most profound sympathy for the parents of James Bulger. But was justice really served?"

Sometimes perpetrators of crime needed help rather than vilification, the author added.

Call to free killers

The letter follows criticism of the Chief Inspector of Prisons Sir David Ramsbotham's call for Thompson and Venables to be freed soon after they are 18.

Sir David this week "apologised unreservedly" to the Home Secretary Jack Straw for speaking out on a subject outside his remit.

The way the trial was conducted is the subject of an appeal by the boy's solicitors to the European Court of Human Rights, who complained the court failed to give them enough allowance as juveniles.