The presumption of innocence finds its evolutionary origins as a constitutional right in chapters 39 and 40 of the Magna Carta. Lord Bingham said that these provisions of our earliest human rights charter “have the power to make the blood race”. Cast an eye over the text and it is easy to see how: “no free man shall be seized or imprisoned or stripped of his rights…” Although the words “presumption of innocence” do not appear in the Charter its DNA is found in the international legal instruments that followed in its wake.

The sophistication of our times makes us complacent about the building blocks of our justice system (perhaps it is as Browning said that as youth ends so does the truth) but Tom Bingham could not have been clearer about their importance, advocating that chapters 39 and 40 should be engraved on the stationery of the Ministry of Justice and Home Office instead of the “rather vapid slogans they now carry”.

The last few days have challenged these basic tenets fundamentally. Abu Qatada, not charged with any criminal offence, has been in custody for several years and even now there is talk of finding a basis upon which his bail can be revoked. Chris Huhne, then a government minister, was the subject of a press conference to announce charges will be brought against him. John Terry was belatedly and it seems without consultation with his manager, stripped of his captaincy because he faces a trial for racial abuse. Harry Redknapp is cleared of cheating the Revenue and in the aftermath there is no regret from those who spent millions chasing thousands (and failing) but insoluble arrogance, “cheat us and we will hunt you down”. It was if the representative of Revenue and Customs had read the wrong script.

In between these events, the respected academic Professor Gary Slapper mooted that innocence  is an absolute and moral concept not a legal one and that in a criminal case no one is ever found innocent.

The dictionary defines the noun “presumption” as “the act of presuming”; the verb “presume” as “to take (something) for granted”. Innocent is defined as “not guilty” and innocence as “the quality or state of being innocent”.

This needs some untangling.

If at its most basic definitional level innocent is not guilty then at least as far as the criminal justice is concerned an acquittal is a declaration of innocence. It does not mean that in a moral sense the acquitted person is innocent (this in any event is likely to be important only to those who seek to exercise moral judgment). It does not even mean the same accused may not be liable in the civil court for the same act: it’s simply a different currency.

The presumption of innocence includes within its meaning that an accused will benefit from it being “taken for granted” that he or she is innocent until a court makes a determination they are guilty. Practically, the issue of someone’s innocence may be treated in a qualitatively different way depending on the facts of the case. Bail is one of the regulators of this: the seriousness of the offence, the accused’s previous convictions, the nature and weight of the evidence pointing to guilt may all be factors that determine whether liberty of the subject is withdrawn pending a verdict. More sinister, some may think, is the use of secret intelligence as a basis for determining whether someone’s freedom can be deprived. Perhaps more troubling, no criminal charge is brought and the hearing that takes place happens behind closed doors, often with the “accused” being excluded – his or her interests protected by a lawyer appointed, paid for and instructed by the government that seeks to bring the case. Should a citizen wish to complain about how this intelligence is gathered application must be made to another secret Tribunal, which does not hear from the applicant, does not tell them what they have or have not considered and does not say how they reach the decision that they have. Some may be forgiven for being reminded of the words of the words of Judge Hathorne in Arthur Miller’s The Crucible “if you know not what a witch is, how do you know you are not one?”

If innocence is taken for granted before guilt is proven then any action, particularly by the State, that may undermine the presumption has to be justified. The real perniciousness of convening a press conference to announce charges of perverting the course of justice against former Energy Secretary Huhne is less that it occurred (although there appeared to be little justification for this exceptional step) and more that the lessons of the recent past had not been learned. Some may recall the press conference last year called by the police and CPS in the North West of England in the wake of the decision to charge Rebecca Leighton with the deaths at Stepping Hill Hospital. Charges against her were later dropped but not before she had spent time on remand, lost her job and had been demonized by the British press: there was no corresponding press conference announcing this extraordinary turnaround of events.

There is something deeply uncomfortable about seeing the police and CPS at the same table at a press conference, particularly before verdict. There is in fact something unsettling about CPS lawyers delivering speeches to the press even after verdict. The prosecution play and important constitutional role: they are independent and, as the Court of Appeal has said, ministers of justice. It has the sense of the Americanisation of the justice process and is not, cannot be a good thing. As a minimum, it is difficult to make the case for it being necessary or justified.

Naturally it is easy for the criticism to be levelled at the purist approach to the preservation of the presumption of innocence that it is naive. To be fair, it is difficult to see how such an observation could be made about Lord Bingham, one of our justice system’s finest legal minds (and who has left a void that has not been filled). That said there needs to some balance achieved: this has not been put better than by legal icon and Harvard Professor, Alan Dershowitz “[t]here is a place for idealism in this world of winner-take-all, but idealism must be filtered through the lens of realism, lest you become naive. There is even room for constructive cynicism, but it, too, must be balanced against idealism and realism. An unrealistic cynic is as naive as an unrealistic idealist, just a lot less noble”.