Horizon IT Inquiry: expert witness faces a 4-day grilling

Image related to Horizon IT Inquiry: expert witness faces a 4-day grilling

Last week saw the Fujitsu IT expert, Gareth Jenkins, give live evidence at the Horizon Inquiry. It was a much-anticipated part of the Inquiry as Mr.Jenkins’ evidence had been central to the prosecutions of some of the sub postmasters and mistresses.

He was challenged closely on his understanding of his role and duty as an expert witness and on the accuracy of his evidence in the original trials.

No findings of fact have yet been made by the Inquiry, so this article will not be commenting on the truthfulness of the witness, but rather on the issues for expert witnesses which have been brought into stark relief by the events of last week.

There are three issues for all experts: firstly, do you have the right expertise to provide evidence; secondly, do you know and understand your role and duty; thirdly, what does it mean to be impartial when preparing written evidence and giving oral evidence.


      1. The right expertise

Mr.Jenkins had been employed by Fujitsu as part of the software design team for the Horizon system. He was a software engineer. He was employed by Fujitsu to help fix issues with the system.

The picture is of a transactional relationship on an issue-by-issue basis, dealing with issues as they arose.

According to his evidence, he did not have overall knowledge of all the operational activity of the Horizon system and he did not have knowledge of all of the faults reported to the Helpline, only of the issues of which he was made aware and then asked to fix.

The evidence he was asked to provide at the prosecutions was about the whole system, not just his part in it.

Expert witnesses need to be very careful to understand the scope of their instructions and the issues they are being asked to deal with. Always be clear exactly what the instructing party is asking you about and then ask yourself if you have sufficient knowledge to be able to provide an opinion on it.

      2. Know and understand the role and the duty

As a longstanding employee of Fujitsu, whose working life was spent responding to, and complying with, requests from his employer, it is perhaps easy to see how he could have applied that same relationship to his role as an expert witness.

Doing so, however, leads to conflict with the duty of the expert witness to help the court on matters within their expertise and to be objective and unbiased (see Crim PR 19.2(1)).

It has emerged at the Inquiry that a letter of instruction was sent to Mr.Jenkins in which his duty was set out. What is unclear is whether or not he read that letter and whether or not he really understood the duty. The evidence given at the Inquiry points to a lack of compliance with the duty.

Instructing solicitors must ensure that their expert witnesses understand that their duty is to the court. Expert witnesses themselves must ensure that they understand that their duty is to help the court. Expert witnesses must energetically and vigilantly guard that duty and make sure that they are complying with it at every stage of their involvement in the case (receiving instructions, writing statements or reports, dealing with requests for clarification or for amendments).

The relationship between the expert witness and their instructing party is wholly different to that between an employee and an employer.

      3. How to be impartial 

Two examples of an apparent lack of impartiality were explored during his testimony to the Inquiry: his knowledge of remote access; agreeing to make changes to his written evidence

(i)             Remote access

Evidence has come to light that Mr.Jenkins knew that it was possible to access the sub postmasters’ and postmistresses’ accounting reports and make alterations without their knowledge but that he did not make that known in his written or his oral evidence at the trials.

That could clearly have had an impact on the prosecutions as one of the central planks of the Post Office prosecutions was that the software was secure and that only the operating sub postmasters and postmistresses could make and alter entries; in other words, only they could be responsible for the entries.

If information is known to an expert witness and it is relevant to an issue in the case before the court, the expert has a clear duty to share that knowledge with the court, freely and openly. The expert is not entitled to wait for a specific question which addresses that information; if the expert knows something, it is within their expertise and they have a duty to help the court by making it known to the court and all the parties involved.

(ii)            Changes to his evidence

There is evidence that he acceded to demands from the Post Office to make changes in his witness statement. For example, he was asked to provide a statement dealing with possible causes of the discrepancies in the accounting figures. He produced a statement saying that, in his opinion, one possible cause was system failure. The prosecution team requested that that reference (described as being “very damaging”) be deleted.

It was duly deleted and did not appear in his final written evidence.

It is legitimate for instructing parties to ask for clarification of an expert witness’ evidence. It is not legitimate to request that an opinion be removed or that relevant information be deleted. No expert witness should accede to such a request.

In relation to both of these issues, there are emails between Mr.Jenkins and the Post Office lawyers (internal and external) seeking guidance on what he should put in his written evidence. When challenged on this approach, his response was effectively that he was not used to working in this environment (ie an expert witness in the criminal justice system).

Expert witnesses must understand that they do not need guidance from their instructing solicitors on what to write in their reports or what to say in court. They can and must only express their own full opinion on all matters that are within their expertise.

If it emerges that an expert witness has altered their evidence at the request of their instructing solicitor, their impartiality will inevitably be subjected to intense scrutiny.

Mr.Jenkins has just been through 4 days of that and it looked like a very uncomfortable experience.