POLICE were understandably jubilant yesterday after bringing Shildon paedophile Thomas O'Carroll to justice, confiscating his "Aladdin's Cave" of child porn and breaking up his international network.

He was jailed for two-and-a-half years.

He will be out within how many months? Eighteen?

Perhaps it is worth reminding ourselves about the point of prison.

Firstly, it is to act as a punishment by depriving a criminal of his liberty. It also acts as a deterrent to those who are tempted to commit similar crimes.

And it protects the public from the behaviour of the criminal.

You may think that two-and-a-half years - or whatever lesser time O'Carroll actually serves - will fulfil none of these points, which is probably why the police admitted they were a little "disappointed" that he didn't receive an indeterminate sentence.

A fourth point about prison is that it should be about re-education and rehabilitation.

O'Carroll is a career paedophile. He has lived a life of delusion, pretending to himself that children are sexual beings who willingly engage in horrible acts with dirty old men.

He must be shown otherwise. He must be confronted with how his disgusting pursuits destroy innocent lives. He must learn how totally the rest of society abhors his beliefs. He must learn that those beliefs are sick and depraved.

Sick - it is an interesting word. Because someone who is sick seeks medical assistance. Castrating people such as O'Carroll would be controversial, but prison should be the place where O'Carroll is taught to control his libido.

The judge has decided that this obnoxious man should return to the community. When he has served his sentence, he should return a changed man - otherwise prison has failed in its duty.

You may well think that an indeterminate sentence - "throw away the key" - may well have been more appropriate, and you would probably be right. Children, wherever they may be in the world, must be protected from appalling men like O'Carroll. The judicial system must now play its part.