Demands for changes to ‘barmy’ rules on digital evidence have government’s ear

The sheer scale of injustice and mendacity in the Post Office Horizon scandal has forced the government to consider fast-tracking changes to the rules on the use of digital evidence in court.

Following a Westminster Hall debate in March, a minister agreed the government would look at the issue and update on progress before and after the summer recess of Parliament.

Westminster Hall debates give MPs an opportunity to raise issues and receive a response from a government minister. They force government ministers to the table and put flags in the ground to say “we are looking at this, we are interested and we expect to see some action”, according to Darren Jones, Labour MP for Bristol North West, who triggered the debate on digital evidence last month.

The Post Office Horizon scandal saw hundreds of people who own and run Post Office branches prosecuted, with some sent to prison based on computer evidence that has since been proved to be wrong. (See timeline of Horizon scandal articles since Computer Weekly broke the story in 2009).

The scandal has already seen the biggest group referral of potential miscarriages of justice to the Court of Appeal, and there are calls for changes in how digital evidence is used in court, backed by evidence of its inadequacy.

Before 1999, prosecutors who relied on digital evidence in court had to prove that the computer system had worked as it should. However, the change to the rules that year meant that it is now presumed the computer worked correctly unless there is explicit evidence to the contrary.

Jones said the Westminster Hall debate had a positive outcome, with an acknowledgement for action to be taken. “It looks like ministers think there is potential to improve this law more quickly over the course of this calendar year,” he said.

The issue has already been raised with the Criminal Procedure Rule Committee chair, and Computer Weekly understands that this has triggered a process of consideration that will take months. But Jones said he is “not entirely convinced the Criminal Procedure Rule Committee has broad enough powers” and that it requires statutory intervention from ministers.

Jones is, however, positive that there could be a faster resolution. “The debate led to a useful discussion with digital minister Matt Warman about what we can do about this. I don’t know what the answer is in terms of what you replace it with, but I recommended it go to the Law Commission.

“The minister suggested that takes too long and this needs to be resolved urgently, which is a good answer from a minister in these circumstances because they normally try to bat you off,” he added.

Jones said court rules have failed to keep pace with technology advances. Today, almost every aspect of life and work involves some digital interaction, but there is little understanding how computers work or why they fail to work properly at times.

“The elephant in the room on this point is that the law has not been effectively updated since the late 1990s, which in the context of technology is barmy,” said Jones. “Technology has been transformed in that period of time, but the rules around digital evidence have not.”

He added that while there have been legislative changes around concerns such as data and privacy, there has not been an update on the law on digital evidence.

The law has not been effectively updated since the late 1990s. Technology has been transformed in that period of time, but the rules around digital evidence have not

Jones was initially made aware of the issue after barrister Paul Marshall wrote to him detailing the issue.

“It is wrong that the law says the computer is always right unless the defence can prove otherwise. The [subpostmaster] defendants really had no power to be able to prove that when they were being prosecuted,” said Jones. “It is clear now that this is one of the biggest miscarriages of justice in British legal history.”

He said that, beyond the rule itself, there are questions about the ability of courts to understand computer-based evidence. “It is also about the competence and capacity of the courts to deal with this type of evidence,” he added. “You would hope, following a miscarriage of justice of this scale, that there will be momentum to try to resolve all these issues.”

Marshall, a barrister at Cornerstone Barristers, has worked on the cases of subpostmasters sent to prison based on flawed evidence, who will hear later this month whether the Court of Appeal will quash their convictions.

He said, among the many failures identified in the Horizon scandal, the failures of the court system are not prominent, but should be.

“While it is a scandal in respect of the sheer mendacity of the Post Office as a public institution, and catastrophic failures in its governance and corporate leadership, it is also a scandal in the scale of the systemic failure of the court system,” said Marshall. 

“Future generations are likely to look askance at English law’s – and English courts’ – apparent inability to engage satisfactorily with digital evidence, an inability that the Post Office scandal has all too painfully exposed.”

He added that if judges are unable to identify whether a trial is fair or not, the whole court system is undermined. “Were courts an airline that failed so frequently, it would be grounded and no one would fly. But there is no choice it’s the only system available,” he said.

Referring to the Post Office Horizon scandal, Marshall said: “That the courts routinely accepted the Post Office’s evidence, suggests that the courts failed in their purpose to effectively test and weigh the relevant evidence. 

“The courts plainly did not do so because the evidence of widespread failure of the Horizon system was not before the court. The reason for this is largely to do with inadequacies in the law concerned with the reliability of computer-generated evidence that took a wrong turn in changes made on recommendation by the Law Commission.

“That the consequence of failure is that large numbers of people were imprisoned and their and their families lives and livelihoods wrecked ought to be a matter of serious public concern.”

Marshall criticised the current government inquiry into the Post Office scandal, chaired by former judge Wyn Williams, which he said will not investigate court failures.

“The inquiry terms of reference do not extend to these critical issues. The reason is almost certainly that, were the question to be answered candidly, it would be the occasion for institutional embarrassment and further erode public confidence in the criminal justice system. 

“Both the courts and the government, for different reasons, have an interest in the hard questions remaining unaddressed and unanswered,” he said.

Marshall added that it is insufficient to blame the Post Office for having abused the processes of the courts when the court itself “should be effective in preventing its process from abuse on this scale”.

Both the courts and the government, for different reasons, have an interest in the hard questions remaining unaddressed and unanswered

“The Post Office, accountable in its conduct of prosecutions to no one but itself, gamed the system for its own advantage for the better part of 15 years – and, from not later than 2015, sought to give the impression that it had not done so, denying all knowledge of just how rackety the Horizon system was, in the hope of brazening it out.

“The Post Office knew, probably from 2010 and indisputably from no later than 2015, that its Horizon system was seriously unreliable and prone to failure. Furthermore, it knew from about 2013 that its prosecutions of its postmasters were in many instances seriously flawed. 

“It stopped prosecuting from 2014, but from that time until 2019 maintained the fiction that it believed the Horizon system was reliable and robust.”

This belief by the Post Office was described by a High Court judge, during a group litigation, as the modern-day equivalent to maintaining that the Earth is flat.

It was that group litigation brought by 550 claimant subpostmasters in the High Court that laid bare the scandal, but the victorious claimants were left just £11m of the £57.75m damages after legal and funding costs were taken out.

“The cost and unsatisfactory outcome for the claimants – where the cost of bringing the claims deprived them of the substantial benefit of bringing the legal proceedings – and the fact that, but for it, the Post Office would have kept the lid on the truth coming out, raise serious questions for the quality and effectiveness of the English justice system,” said Marshall.

Stephen Mason, a barrister no longer in practice, has been researching and recommending change on the use of electronic evidence in court since 2004.

He said that the Horizon scandal has exposed serious weaknesses in the English legal system in relation to the way evidence from devices controlled by software code is assessed and judged.

“It is getting worse: just think what software controls now, including motor vehicles. Just one example – ask a police officer whether they routinely check the software in motor vehicles have been involved in collisions, etc, and how little they know and that they rely on the manufacturers,” said Mason.

“I suggest the Minister of Justice treat this is a serious issue, because the problem cannot conceivably only have caused problems with the Post Office prosecutions. For instance, the Crown Prosecution Service still consider the following to be correct: ‘Computer evidence must now follow the Common Law rule, that a presumption will exist that the computer producing the evidential record was working properly at the material time and that the record is therefore admissible as real evidence.’” he added.

Mason said that there are two options for the government to make changes: “First, for the Court of Appeal, perhaps in the 23 April 2021 judgment of subpostmaster appeals, to explicitly overrule the presumption. This would have an immediate effect. Second, for the Law Commission to revise the presumption and make appropriate recommendations. This will take longer, but will enable the development of suitable guidelines to help judges. In the meantime, the Crown Prosecution Service advice relating to this topic should be revised as a matter of urgency in the light of the objective evidence.”

On 23 April, 42 subpostmasters, prosecuted for financial crimes based on evidence from the flawed Horizon system, will hear if their convictions are quashed. In December 2020, six subpostmasters, who were originally prosecuted in a magistrates’ court, had their convictions quashed in Southwark Crown Court.