Last week's judgment in the Paul Ward case was of great significance with respect to two aspects of the criminal justice process.
Much attention has been focused on one of these aspects - the "supergrass" role of Charles Bowden. Bowden is the first witness to benefit from the State's new witness protection scheme and is clearly central to the prosecution strategy against the alleged conspirators in the killing of Veronica Guerin.
Bowden is serving six years for his part in the conspiracy, a sentence which amounts to a considerable reduction on what he might have expected if he had not co-operated with the prosecution. The prosecution is following the English rather than the Northern Irish model in the use of a supergrass, to the extent that the accomplice-witness has not been granted full immunity and the conspirators are being tried separately.
However, most controversially, the Special Criminal Court diverged in the Ward trial from the English practice by convicting solely on the evidence of an accomplice-witness.
Since 1977, this has not been accepted practice in England and Wales because of the obviously heightened danger of a miscarriage of justice in a conviction based only on testimony from a questionable, criminal source.
While this controversial decision raises important new issues which need to be addressed, the second aspect of the judgment highlights a problem which has for several years been of growing concern to jurists, civil libertarians and even the European Committee for the Prevention of Torture but, unfortunately, of less interest to the general public - Garda handling of suspects in custody and under interrogation.
The Special Criminal Court rejected Ward's alleged confession of guilt as inadmissible and, indeed, went so far as to state that Ward may never have made any such confession. This appears to be a clear suggestion that the Garda Siochana was not giving truthful evidence and may well have been, to use the argot, "verballing" Ward; that is, putting words in his mouth.
The judges also found reason to believe Ward may have been subjected to undue psychological pressure during interrogation. Three points can be made about this profoundly disturbing judicial scepticism about Garda procedures and evidence. First, the doubts raised about Garda procedures in the Ward case are by no means isolated. In fact, that case is just the latest in a long line of disquieting cases which give real cause for concern that Garda zeal to obtain convictions may be undermining Garda determination to maintain scrupulously fair and impeccably honest procedures in the handling of criminal suspects.
Second, the explicit acknowledgement by the judges of the power of purely psychological techniques to extract a false admission is to be welcomed. This is an important advance on the traditional legal position, which is alert to physical oppression, brutality and clear-cut inducements, but tends to ignore the subtle, often more effective, forms of psychological pressure which can persuade an innocent person wrongly to confess guilt.
Third, the case draws attention once again to the incredible delay in the introduction of routine, compulsory audio or video-taping of Garda interrogations.
Such taping is not a fail-safe method for ensuring the validity of confessions, but it is a straightforward and sensible measure which promises to be of some benefit both to the trial process, by providing more certain evidence about suspects' statements, and to the Garda, by reducing malicious accusations against it.
Equally important, it promises to be a limited but useful check on possible Garda abuses against suspects.
It is customary when discussing the issue of false confessions to hark back to the days of the "heavy gang" and the Nicky Kelly and Kerry babies cases.
Unfortunately, despite a long, expensive tribunal which examined how Joanne Hayes and her family had come to confess to a murder they did not commit, the important lessons about the inherent unreliability of retracted, uncorroborated confessions and about the need for very stringent, independent checks on Garda detention and interrogation, have still not been learnt.
As a consequence, the system continues to throw up disquieting instances of induced false confessions and of dubious Garda handling of the detention and interrogation of suspects. The recent Dean Lyons case is a classic example. Here, the Garda had somehow managed to obtain from him a confession to the murder of two women.
The Garda acted as if this confession were true until, and indeed for some time after, another man confessed to the murders with convincing detail which, it appears, could be known only to the murderer.
In another murder case against Damien Marsh, the prosecution collapsed when the two gardai, who had supposedly recorded a confession, totally contradicted each other in court about how they had recorded it. The statement had also disappeared and could not be produced in court.
There are other worrying cases. The Court of Criminal Appeal has recently overturned convictions in the Pringle and Connell cases because of concern about the methods and results of interrogation. One of the suspects in the Garda Jerry Mc Cabe murder was taken to hospital three times while in Garda detention and was suffering from memory loss, seemingly due to concussion, at his first appearance in court.
On the morning of the arrest of Patrick Holland, who has already been convicted on the word of Bow den, Holland's solicitor was arrested and in effect prevented from providing counsel to his client while he was in Garda custody.
Even civil libertarians appreciate that the Garda Siochana have has recently come under intense pressure to achieve results because of public and political concern about particularly atrocious crimes and, more generally, about drug-related, organised crime.
It is also relevant that the legislature has provided the Garda with considerable new powers which are, perhaps unwisely, intended to shift the balance in the criminal process and make convictions more likely. Indeed, this process is continuing with current proposals to dilute the "right to silence".
The growing catalogue of questionable incidents, however, suggests an unhealthy Garda culture, focused exclusively on getting the man regardless of the method, may be developing in some parts of the force, with the risk of making miscarriages of justice more likely.
The views of the judges in the Ward case should surely set off al arm bells and alert us to the need for a thorough evaluation both of our system of checks on Garda interrogations and of the effects of recent changes on the integrity of the rule of law, particularly on the basic principle of the presumption of innocence.
A strong case can be made that what we need is a tighter and not a looser legal framework for the control of Garda interrogation.
While there will undoubtedly be an immense sense of public relief and perhaps even satisfaction when Veronica Guerin's killers are behind bars, it would be disastrous if this were done by easing the burden of proof on the prosecution and so undermining public confidence that the convicted were in fact guilty.
The Garda must not take the strong public support for its work and the political willingness to increase its powers as a signal that short cuts or dubious practices can be tolerated. It is precisely when there is an emotive and pressured atmosphere that the Garda must re double its efforts to ensure adherence to due process and fair procedures.
Dr Paul O'Mahony is a lecturer in psychology in the school of occupational therapy, TCD, and author of Criminal Chaos: Seven Crises in Irish Criminal Justice