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Martin Kenney

Head of Firm , Martin Kenney & Co

Tony McClements

Head of Investigations, Martin Kenney & Co

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Although many convictions were subsequently quashed, the damage to lives and families has been immeasurable

Failure to disclose can damage cases and – sometimes – lives

Failure to disclose can damage cases and – sometimes – lives

By and

Martin Kenney and Tony McClements discuss how the Horizon IT scandal illustrates the inherent difficulties in managing clients, complainants and witnesses

Regardless of whether you are a lawyer or a member of law enforcement, prosecuting a case can be a veritable minefield when managing clients, complainants and witnesses.

To take a case in point: between 1999 and 2015 the Post Office prosecuted 736 postmasters and sued a further 555 for alleged theft, fraud and false accounting. After convictions that led to many being jailed and others declaring bankruptcy, it was revealed that the Post Office accountancy software upon which the prosecutions were based – known as the Horizon IT system – had systemic faults that showed supposed shortfalls in returns.

The background

The ensuing Horizon IT scandal, described as ‘the most widespread miscarriage of justice in UK history’, has led to 86 wrongful convictions being overturned (so far), with more than £21m paid out in compensation (and more to come). It may lead fellow lawyers to recall incidences where clients have deliberately withheld material information, on the basis that they did not want to undermine their own case. This absence of candour can at best leave lawyers fighting with one hand tied behind their back, at worst facing a ticking time bomb that could, at any point, explode during court proceedings.

In the Horizon scandal, sub-postmasters (SPMs) began reporting unexplained discrepancies and losses associated with the Horizon IT system after its introduction in 1999. Yet, the Post Office maintained that Horizon was ‘robust’ and insisted that none of the discrepancies were due to the software. On that basis, it proceeded to prosecute and sue many SPMs.

Not only has it since been alleged that the organisation chose to turn a blind eye to problems with Horizon, but information was also withheld from accused SPMs that would almost certainly have assisted them in mounting a stringent defence against the allegations they faced. In doing so, there was a failure to comply with disclosure obligations under the Criminal Procedure and Investigations Act 1996. Effectively, the SPMs were made scapegoats because the Post Office refused to admit that the system and its results were corrupted.

The implications

Although many convictions were subsequently quashed, the damage to lives and families has been immeasurable. What this case illustrates is the problem of complainants and witnesses only telling lawyers and investigators what they think the lawyers and investigators need to hear.

In this instance, the judge presiding over a public inquiry into the disaster, Sir Wyn Williams, has already threatened criminal sanctions against the Post Office for what he perceives as its failure to disclose information promptly to the inquiry.

As lawyers and investigators, it falls to us to stand in front of the court and confirm that we have presented all the information available. But each time we do so, we can experience that nagging feeling that perhaps our client, complainant or our witness has ‘forgotten’ to mention something of significance.

The Post Office case appears to have plenty of such instances. In September, Richard Morgan KC, who worked on one of the civil cases, gave evidence to the inquiry that he had not been advised by the Post Office of any issues with the Horizon system and the financial information it had generated. Morgan stated that had he been advised of these concerns, he would have presented his case differently.


Our clients are diverse in nature. They can range from well-read, sophisticated businesspeople and public sector professionals who understand how litigation works, all the way to the naive small investor, who is filled with trepidation at the prospect of going to court. Which of these clients is preferable?

You may have an individual who will analyse your decisions and inevitably try to take the lead and assert control over your strategies; you might also deal with a person who hangs on your every word, but who understands very little of what you say.

Those clients occupying the middle ground can be equally problematic. There is an adage that ‘a little knowledge is a dangerous thing’. These clients can often interfere with your strategy, second-guessing everything and anticipating problems that do not exist. Worse still, they can create problems that should have been avoided.

The one thing they all have in common is the human psychological desire to vindicate or defend a position. That element yields a reluctance to disclose all that should be told if they perceive that it may undermine their position.

What they all have in common is the potential to cause embarrassment and to damage professional reputations. If a client decides to withhold information for whatever reason, we can be left to pick up the pieces. And, as with the Horizon scandal, lives can be left devastated.

Martin Kenney and Tony McClements are head of firm and head of investigations, respectively, at Martin Kenney & Co