Just to be Devils' Advocate for a second...
Whilst it is imperative that such acts are, rightly, prosecuted and punished within the full ability of the law, my concern lies with the media age in which we live. It seems to be far to easy to judge the defendants by todays standards, rather than by the standards at the time of the offences
Is the average age of the jury known in the case of Mssrs Hall and Harris? Given both men are around 80, a jury of their peers should be people in their late sixties and over 
Equally, if historical prosecution is acceptable in its current form, why is Sinn Fein a player in politics
Surely being a member of such an organisation is an offence under the Terrorism Act, and why are the disappeared not being investigated for the actual crimes they are, with no fear of prosecution for anyone in the province in the context of the troubles 
Makes no sense...
No, the IRA is an illegal organisation not Sinn Fein which is now a perfectly accepted and respected political party. So membership is not illegal.
As for historical facts being taken into account, the Good Friday Agreement drew a line on what had transpired before in the Republicans struggle for a unified Ireland with all that entailed in the form of "illegal" acts. It also drew a line on what the British had undertaken, sometimes of very questionable legal standing. All parties had committed illegal acts in a war, so to achieve reconciliation all agreed to move forward.
This was a political, national, action which bears no relationship with individuals who have committed illegal acts with women and young children were there is no statute of limitations. Therefore legal action can still proceed over "historical" cases.
As for the jury question. I think it is rather ironic that these generally older men, who took advantage of the young, are now being judged by a younger element. In any case, why should an older jury member reach a different decision on guilt than a younger individual. A disgusting, illegal and destructive act is going to be just that no matter who the jury is.
