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Government wrong to pass the buck on computer evidence reform

IT expert James Christie tells Computer Weekly why he is disappointed that the government has no plans to change the rules on the use of computer evidence in court

The response from the government to Labour MP Kevan Jones about the presumption of reliability of computer evidence is very disappointing. This looks like the government is buying time and passing the buck to Wyn Williams, who is running the Post Office inquiry. The case for reforming the presumption is overwhelming and the government should have the resolve to initiate reform without waiting to see what Williams says.

This is not just about the Post Office’s Horizon system. The presumption betrays a dreadful naivety on the part of the legal system about the difficulties of working with fallible, complex software systems.

The strongest justification, in fact the only real one, for retaining the presumption is that it is a pragmatic response to the problems involved in proving the reliability of a complex computer system. The presumption, therefore, is a necessary trade-off, balancing the difficulties of making categorical statements about system behaviour against the need for courts to operate efficiently. It is an evidential presumption, the argument goes, that can be rebutted rather than a rigid rule.

However, this presumes that the party producing the evidence provides full disclosure of information that would allow the other party to challenge the evidence. It also presumes that the other party has the financial and technical resources to mount a successful challenge. Both presumptions were shown to be baseless in the Post Office scandal. The Post Office withheld relevant information and the defendants were denied any means of challenging the evidence. It is not a pragmatic response, it is cynical. It buys some convenience for the courts at the price of justice, and at a dreadful human cost.

I agree that it would be impractical simply to scrap the presumption and require the providers of computer evidence to prove its reliability in every case. What would be more practical would be a two-stage process requiring evidence providers to provide information about known errors and to demonstrate that they are in control of their systems, ie that they have developed, managed and audited them responsibly. If they cannot show the court such evidence, then they should be required to prove the reliability of any computer evidence they offer.

When I started as an IT auditor, I was taught the auditor’s motto, “Don’t tell me – show me”, ie don’t offer me bland reassurance that everything is OK – show me the proof. Corporations must be prepared to prove that they are in control of their IT.

I don’t see how it is right that corporations can manage their IT incompetently, as was the case with the Post Office and Fujitsu, and still expect the courts to accept that their computer evidence is 100% reliable.

Last year, I contributed to a paper submitted to the Ministry of Justice which argued for such a two-stage reform. The lack of positive response has been very disappointing.

It is time for the government to tell the cowboys that the Wild West of IT has to be cleaned up. I’m sure Wyn Williams would not want to be called the new sheriff in town, but I doubt if the government has the resolve to take on that job without some serious prompting.

If this presumption is not reformed, the Post Office scandal will not be the last. It is long past time to act, and it is very disappointing to see the government playing for time.

James Christie is an independent consultant, an IT expert with extensive experience of software development, IT audit, testing and security management in the IT outsourcing industry going back to the 1980s.

Timeline of the Post Office Horizon scandal articles since Computer Weekly first reported on it in 2009 

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