Twenty-seven years ago, the Law Commission made a decision to trust computers. They concluded that a provision in the Police and Criminal Evidence Act, which required evidence generated by a computer to show that the system was working properly, was unnecessary. Instead, they believed in a “presumption of proper functioning.” This decision was supported by the government and the provision was repealed in 1999.
However, specialists in IT law now believe that the Law Commission’s analysis was flawed. Dr. Sam De Silva, a partner at CMS and former chair of the Law Society’s Technology and Law Committee, stated that the commission misunderstood the nature of software, hardware, and IT systems. He believes that their interpretation was misguided and led to the repeal of the provision.
The tipping point came in 2019 with the judgment in Bates v the Post Office, which revealed that innocent people were wrongly imprisoned due to presumptions about the reliability of the Horizon computer system. Barrister Stephen Mason and other legal experts had been warning about the dangers of blindly trusting computers for decades.
In November 2020, a group of nine experts, led by Paul Marshall of Cornerstone Barristers, issued a report warning the government about the dangers of presuming that computers always work correctly. They argued that this presumption is unrealistic and unsafe. They also highlighted that computer errors are not always immediately detectable or caused by incorrect data entry.
The report made several recommendations, including strengthening obligations for disclosure and requiring parties to collaborate in the disclosure process. It also suggested that courts should consider the reliability of computer evidence in the context of other available evidence.
Despite the report being referred to relevant authorities, no action has been taken so far. However, it is clear that a new approach to handling computer-derived evidence may be necessary, especially with the rise of artificial intelligence software. Some experts suggest subjecting IT designers to ethical standards similar to other professions, while others propose legislation to register programmers of “serious systems.”
In 2018, Sir Geoffrey Vos, then chancellor of the High Court, predicted that computer-generated evidence would greatly reduce court disputes over primary facts in the future. However, it seems that this prediction was premature.
Overall, there is a growing consensus among IT law specialists that the presumption of proper functioning for computers in legal proceedings is flawed. The potential flaws in computer evidence and the need for a new approach are becoming increasingly apparent.