Artificial intelligence triggers frothing excitement in legal circles, but the role of older technology is still being debated. Ministers have unveiled a review of how computer evidence is used in court. After the Post Office Horizon scandal, there are concerns that presumptions about the reliability of technology could lead to future miscarriages of justice.
The justice minister Sarah Sackman KC is reviewing the accuracy of digital evidence in courts. Its role in the criminal justice system — especially the presumption that computers cannot be in the wrong — is to go under the microscope. Earlier this week, the Ministry of Justice highlighted the Post Office Horizon scandal as officials said that the review was a bid “to prevent future miscarriages of justice”.
It was the previous Labour government that set this hare running more than 25 years ago. Before 2000, the common law position was that computer evidence could be admitted in criminal proceedings only if it could be demonstrated that there were no reasonable grounds for believing that the statement was inaccurate because of improper use of the technology.
The other requirement was that the court needed to be satisfied that at all material times the computer was operating properly — or if not, that any glitch had not affected its overall accuracy.
But after Tony Blair’s landslide in 1997, the Law Commission — the independent body that advises ministers on reform in England and Wales — recommended that those provisions be replaced with a rebuttable presumption that computers operated correctly at material times. The law was reformed by the Police and Criminal Evidence Act 1984.
The latest crop of Labour justice ministers want to assess whether that presumption has gone too far. Many sub-postmasters would have no difficulty answering that question — and the ministry has said that the aim of the review is to achieve the “overarching objective” of ensuring “fairness and justice for all those involved in prosecutions”.
Officials want to understand “the ways in which evidence produced by software is handled in criminal proceedings” — an awareness that some might suggest they should already have — and that they will assess the position in other jurisdictions before reporting.
To be fair to the Blair government, the late 1990s was a far-away age in terms of technological evolution. And as the Ministry of Justice says, in the modern world digital material “proliferates” in criminal cases — particularly in fraud, rape and serious sexual offence investigations.
Officials note that of the previous restrictions on the admissibility of computer evidence — which dated from the Police and Criminal Evidence Act 1984 — “it could … be construed to include everything from the complex accounting software used by commercial banks to text messages, email chains and social media posts”.
The ministry says that it wants any reform to the present presumption to be “carefully defined to only include that evidence which is generated by software, including artificial intelligence and algorithms”. Examples include accounting programmes such as Horizon, automated fraud or plagiarism detection software, and automated reporting based on records entered into devices, including handheld gadgets for entering patient details in hospitals.
Officials say they are inclined to exclude evidence that is captured or recorded by other types of devices, such as text messages or messages sent through web-based services, social media posts and emails. They would also exclude digital photographs and video footage, breathalyser readouts and mobile phone extraction reports.
“We must learn the lessons of the Post Office scandal,” said Sarah Sackman KC, a justice minister, as she launched the review. Sackman added: “A blanket no-questions-asked acceptance of the accuracy of digital evidence can have a devastating impact on people’s lives. We need to carefully consider how we can both use and interrogate digital evidence in court.”
Ministry officials note that the Post Office scandal — which was Britain’s biggest miscarriage of justice — was caused by “deliberate failures to properly interrogate and disclose evidence, which prevented postmasters and others from effectively challenging the reliability of the Horizon computer system evidence”.
They add that any changes to the existing legal presumption “could mean defendants are better equipped to interrogate computer evidence against them, and would put more onus on the party supplying the digital evidence to ensure it can stand up to scrutiny”.
And they emphasise that it is “vital that, in making any changes to the law in this area, we are clear on how we are defining such evidence, to avoid unintentionally bringing into scope anything which should not be included, or indeed excluding anything which we do consider should be in scope”.
Law chiefs embrace the review. Christina Blacklaws, a former Law Society president who is the head of LawtechUK, a body funded by the Ministry of Justice, said that it is “essential” the presumption is reviewed. “The law must evolve in line with society and technology,” she says. “This presumption belongs to a bygone age when our use of technology was less pervasive and complex.”
Mary Prior KC, the chair of the Criminal Bar Association, is more robust. She says the review is welcome “because it recognises the inherent danger of assumptions about computers and the difficulties faced by those accused of fraud, theft and other offences where the evidence primarily consists of what a computer shows”.
But Prior takes a more aggressive swipe at the Post Office, cautioning that the ministry’s review “must work in tandem with any prosecution authority understanding its statutory duties to disclose information which brings the accuracy and reliability of devices into question”.
She adds: “We must never face another situation where those conducting private prosecutions do so without apparent knowledge of the basic laws of disclosure and their duties as prosecutors. Private prosecutions by a purported victim involved in the proceedings are fraught with conflict. It is time for a different mechanism.”
The deadline for submissions to the government’s “call for evidence” is April 15.
Jonathan Ames Legal Editor;Thursday January 23 2025, 12.01am GMT, The Times