British Post Office computer system scandal

[Akira Urushibata]

In 1999 the British Post Office installed a computer system named
"Horizon".  From the early training phase problems were reported, but
the upper management at both the Post Office and developer Fujitsu
failed to take corrective measures.  As a result Horizon kept
providing phony reports of lost funds in branch offices.  The Post
Office responded aggressively to these reports by prosecuting managers
of these offices.

Subsequent investigations have brought to light disturbing details.
During prosecutions the Post Office had claimed that only branch
masters had access to the financial data in Horizon but this was
untrue: a back door existed which gave engineers access to these
figures.  They had withheld relevant code and data from courts.
They had also lied to those accused, claiming that theirs were
isolated cases when in reality there were over 700.

This looks like a showcase of what harm can be done by refusing to
disclose code and data and by keeping victims helpless by isolating
them.

---

Post Office scandal: What the Horizon saga is all about - BBC News
22 March 2022
https://www.bbc.com/news/business-56718036

   Between 2000 and 2014, the Post Office prosecuted 736
   sub-postmasters and sub-postmistresses - an average of one a week -
   based on information from a recently installed computer system
   called Horizon.

   Some went to prison following convictions for false accounting and
   theft, many were financially ruined and have described being
   shunned by their communities. Some have since died.

   After 20 years, campaigners won a legal battle to have their cases
   reconsidered, after claiming that the computer system was flawed.


   What was Horizon?

   Horizon was introduced into the Post Office network from 1999. The
   system, developed by the Japanese company Fujitsu, was used for
   tasks such as transactions, accounting and stocktaking.

   Sub-postmasters complained about bugs in the system after it
   reported shortfalls, some of which amounted to many thousands of
   pounds.

   Some sub-postmasters attempted to plug the gap with their own
   money, even remortgaging their homes, in an (often fruitless)
   attempt to correct an error.


   What was the effect on individuals?

   Many former postmasters and postmistresses have described how the
   saga ruined their lives.

   They had to cope with the long-term impact of a criminal conviction
   and imprisonment, some at a time when they had been pregnant or had
   young children.

   Marriages broke down, and courts have heard how some families
   believe the stress led to health conditions, addiction and
   premature deaths.

   ...

---

Post Office accused of withholding documents from IT scandal inquiry
https://www.theguardian.com/business/2022/oct/11/post-office-accused-of-withholding-documents-from-it-scandal-inquiry

   The Post Office has been accused of withholding thousands of
   documents from the inquiry into an IT scandal that led to more 700
   unsafe convictions.

   The Post Office IT inquiry resumed on Tuesday with a strongly
   worded row over the failure to disclosure more than 30,000
   documents. Lawyers for the unfairly convicted operators accused the
   Post Office of continuing to deploy "malevolent" tactics to
   frustrate justice.

   They also called for the inquiry to be adjourned until all the
   relevant documents were made available.

   A lawyer for the Post Office strenuously denied the claims. The
   dispute provided a foretaste for what is set to be a hotly
   contested second phase of the inquiry into one of the biggest
   miscarriages of justice in British legal history.

   Edward Henry KC, representing one group of post office operators,
   suggested the Post Office needed to be trained to comply with
   disclosure orders.

   ...

---

Postmasters were prosecuted using unreliable evidence
8 June 2020
https://www.bbc.co.uk/news/uk-52905378

   ...

   Evidence from the system was still used by the Post Office to
   secure convictions against postmasters like Seema Misra.

   She was pregnant when she was sentenced to 15 months in prison in
   2010 for stealing -L-74,000 from her branch in West Byfleet.

   At her trial, the Post Office argued computer errors could not be
   responsible for the missing money.

   But [BBC] Panorama has seen internal Post Office emails which show
   its legal department was told about Horizon errors shortly before
   her trial.

   One email from the Post Office Security Team to the Criminal Law
   Team is about a bug in the Horizon computer system that makes money
   "simply disappear". In one case, -L-30,611 went missing.

   The security team tell the legal team they are worried the bug may
   have "repercussions in any future prosecution cases".

   An attachment to the email says that "any branch encountering the
   problem will have corrupted accounts".

   The document was printed out by the Post Office legal department
   just three days before Seema Misra's trial, but it was never
   disclosed to her defence.

   ...

Note: In some countries prosecutors have a "right" to withhold any
evidence that favors the defendant.  In Japan the "right" is commonly
practiced to the fullest extent, leading to an extremely high
conviction rate.  It seems that this is not the case in UK but I am
not sure about the details.

Wherever prosecutors have this "right", the defendant is burdened with
the responsibility to prove himself or herself innocent.  This is often
an uphill struggle.

---

Fujitsu: How a Japanese firm became part of the Post Office scandal
https://www.bbc.com/news/business-61020075

   As the public inquiry into the scandal continues, Fujitsu's legal
   representatives will make their opening statements on Friday. So
   how did a Japanese company, generally known to Brits as a maker of
   laptops, become embroiled in one of the most widespread
   miscarriages of justice in UK legal history?

   It may be difficult to believe, but in Fujitsu's home market,
   hardly anyone has heard of the Horizon scandal.

   ...

---

https://en.wikipedia.org/wiki/British_Post_Office_scandal

There is one detail in this Wikipedia article which is hard for those
outside UK to understand.  It appears that the Post Office has the
authority to assume the role of prosecutor in certain cases.