The Post Office failed to disclose material to one of its lawyers that would have resulted in her advising dropping the case against a worker who was then convicted, tried to overdose and became homeless, the inquiry into the Horizon IT scandal has heard.
Teresa Williamson, a Post Office lawyer involved in the prosecution of Lisa Brennan, said she now knows upper management were aware of potential bugs and problems with the Horizon IT system but never told those pursuing cases against branch operators who were wrongfully convicted of stealing.
“I trusted within the Post Office that if I asked for evidence to be obtained it would be obtained,” she told the inquiry into the scandal, often described as the most widespread miscarriage of justice in UK history.
“I trusted that if there was unused material to be disclosed that would be provided to me by the investigator. Looking back, knowing what I know now … I realise there was a lot of material that wasn’t disclosed to me and things I should have known about that I didn’t know about.
“We should have been told these things. I understand there were discussions at board level about reliability of the Horizon system and that was not filtered down to the criminal law team.”
Williamson was involved in the prosecution and conviction of Brennan, a woman who worked as a counter clerk at a post office in Huyton, Merseyside. After the Horizon IT system detected a shortfall of £3,000 she was suspended and summonsed to appear at court on Christmas Eve in 2002.
Ultimately, she was found guilty on 27 counts of theft, suspended for two years. She tried to take an overdose, her marriage broke down, she became bankrupt and the family home had to be sold, leaving her homeless. Her conviction was finally overturned in 2021.
“I assumed the data that formed the key basis for the decision to prosecute Ms Brennan was entirely accurate,” said Williamson. “Had I known then what I know now about the Horizon system, it is almost certain that this advice would have recommended that no further action was taken against Ms Brennan.
“I have little doubt that in the Lisa Brennan case I would have advised that there was not a realistic prospect of conviction. I personally feel let down by any individuals who failed to share this information with prosecutors or the criminal law team generally.”
Williamson moved out of the Post Office’s criminal law team at the end of 2003, moving to a role in the company’s employment team, and left the business around Christmas 2005.
She said it was only in 2009 when she read an article in the media about the scandal that she became aware of the IT issues with the Horizon system that underpinned the Post Office’s cases against postmasters.
“I was not aware of any bugs, errors, defects or problems with the Horizon system at any point throughout my involvement in this prosecution,” she said. “From my perspective as a lawyer, knowledge of these issues would have changed my approach to any prosecutions that I conducted involving Horizon data.
“I feel gutted that I was unwittingly part of a horrible miscarriage of justice and am so sorry for the awful impact it has had on her life.”
The Horizon scandal resulted in more than 700 post office operators being prosecuted between 1999 and 2015 for theft, fraud and false accounting because of faulty accounting software installed in the late 1990s.
To date, 86 operators have had their wrongful convictions overturned and £21m has been paid in compensation.
