The Justice Secretary has been urged to scrap a law that was backed by the Post Office and requires courts to presume that evidence derived from a computer is reliable.
MPs and campaigners for the sub-postmasters wrongly convicted of financial crimes say Alex Chalk must amend the law to prevent a repeat of what happened to them.
The Post Office lobbied for the rule in the 1990s before the scandal in which hundreds of sub-postmasters were convicted of theft, based on evidence from the Horizon computer system used in their branches.
This evidence was later proved to be unsafe owing to errors in the software that created account shortfalls, for which sub-postmasters were blamed and some jailed.
Nearly 100 people have so far had their convictions overturned and the Government is considering exonerating hundreds more.
The current legal rule stipulates that courts should presume a computer system has operated correctly unless there is explicit evidence to the contrary.
It replaced a law which said that prosecutors using evidence derived from computers had to verify that the system it came from was working correctly. It was introduced in 1999 by the then Labour government following a Law Commission recommendation.
Documents that the Post Office submitted to the Law Commission in 1995 show that it viewed these “technical requirements” as a barrier to successful prosecutions.
‘Law is outdated’
Campaigners want the legal rule replaced by a requirement placing the onus on prosecutors like the Post Office to show that any computer system is operating correctly if they are going to rely on evidence from it.
Kevan Jones, the MP who has led the campaign to clear the sub-postmasters, said the current rule was outdated.
“The way in which computers are classed in court is archaic and more or less says they can never be wrong,” he told The Telegraph. “It takes no consideration of software or coding issues.
“The law needs to be changed. I understand there have been calls for this from members of the judiciary who are aware the law is outdated. It is not just Horizon, it is similar with bank fraud cases.”
Barrister Stephen Mason, editor of Electronic Evidence, a practitioner text for judges and lawyers, also backed a change in the law.
“The presumption ‘magics’ computer output into truth. This presumption is absurd because all complex software contains many errors,” he said.
“The burden of proof is reversed. Showing the contrary, as the Post Office Horizon scandal attests, can be a burden that a defendant to a criminal charge or civil claim will rarely be able to discharge, because they have no direct knowledge of the computer system.
“To stand any chance of challenging computer evidence, a defendant must be given appropriate disclosure of relevant evidence of the system. It is a poor excuse to claim that it is expensive to provide routine information relating to computer bugs. The fairness of legal proceedings should be paramount.”
‘The truth is the precise opposite’
Mr Chalk commissioned a paper in August 2020, when he was a junior minister in the Ministry of Justice, on suggestions for improving the existing approach to the proof in court proceedings of computer-derived evidence.
It was written by barrister Paul Marshall, who represented sub-postmasters who successfully overturned their wrongful convictions.
It recommended that a prosecutor, like the Post Office, which deploys electronic evidence should automatically provide sufficient details of their systems to demonstrate that they were professionally managed.
However, in May 2022, the then justice minister James Cartlidge disclosed that the Government had “no plans to review” the presumption as it had a wide application and was “rebuttable” if there was evidence to the contrary.
It is understood officials argued it was akin to presuming that, for instance, breathalyser results or forensic tests were accurate unless proven otherwise.
Mr Cartlidge said the current public inquiry into the Post Office scandal would advise the Government on the matter.
“Given the concerns raised about the Post Office’s Horizon IT system, the Government wants to be fully assured that there is a public summary of the failings associated with the system and that lessons are learnt from this dispute,” he said.
Mr Marshall accused the Government of being “indifferent to the wreckage that the presumption caused.”
He said there was a fallacy that most computer errors were visible or apparent to an operator and that most errors were the result of operator input.
“The massive Post Office group civil litigation showed that the presumption is simply wrong. The truth, as any computer or software engineer will tell you, is the precise opposite of the presumption,” he told Computer Weekly.
Title: Justice Secretary Urged to Reconsider Law on Computer Evidence
The Justice Secretary, Alex Chalk, is facing calls to revise a law that presumes evidence derived from computers to be reliable. This law, which was supported by the Post Office, has come under scrutiny following the wrongful convictions of sub-postmasters for financial crimes. The convictions were based on evidence from the Horizon computer system used in their branches, which was later found to be flawed due to software errors.
Nearly 100 people have had their convictions overturned so far, and the government is considering exonerating hundreds more. The current legal rule assumes that a computer system has operated correctly unless there is explicit evidence to suggest otherwise. This replaced a previous law that required prosecutors to verify the functionality of computer systems when using evidence derived from them.
Campaigners are advocating for a change in the legal rule, placing the burden on prosecutors like the Post Office to demonstrate the correct operation of any computer system they rely on for evidence. Kevan Jones, the MP leading the campaign, argues that the current rule is outdated and fails to consider software and coding issues. Barrister Stephen Mason supports this view, stating that the presumption of computer output being truthful is absurd, as all complex software contains errors.
Alex Chalk commissioned a paper in 2020 to explore improvements to the proof of computer-derived evidence in court proceedings. The paper, written by barrister Paul Marshall, recommended that prosecutors deploying electronic evidence should provide sufficient details of their systems to demonstrate professional management. However, the government has stated that there are no plans to review the presumption, claiming its wide application and rebuttable nature if contrary evidence exists.
The ongoing public inquiry into the Post Office scandal will advise the government on this matter. Paul Marshall accuses the government of being indifferent to the damage caused by the presumption and highlights that most computer errors are not visible or apparent to operators. He emphasizes that the truth is contrary to the presumption and calls for fairness in legal proceedings.
It remains to be seen whether the Justice Secretary will take action to address these concerns and ensure a fairer approach to computer evidence in court proceedings.