Post Office pushed for law that says computers are never wrong

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 legal 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.

Current law stipulates that courts should presume a computer system has operated correctly unless there is explicit evidence to the contrary.

It replaced a rule 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.

Campaigners want it 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, told The Daily Telegraph: “The way in which computers are classed in court are both archaic and more or less says they can never be wrong. 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 I understand there have been calls for this from members of the judiciary who are aware the law is outdated.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, said: “The presumption ‘magics’ computer output into truth. This presumption is absurd because all complex software contains many errors.

“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.”

Mr Chalk commissioned a paper in August 2020, when he was a junior minister, on suggestions for improving the existing approach to computer-derived evidence.

However, in May 2022 the then justice minister James Cartlidge said 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.

Nonetheless, Mr Cartlidge said the 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 at the time.

‘The law needs to be changed. It is not just Horizon, it is similar with bank fraud cases’