Context
Mr Justice Fraser’s December 2019 High Court judgment in Bates & Others v Post Office was the technical-evidence turning point in the Post Office Horizon scandal. The judgment found that the Horizon IT system had been unreliable — the finding that subsequently enabled the Court of Appeal to quash hundreds of sub-postmaster convictions from 2021 onwards.
The litigation template
The 2017–2019 litigation was a civil group action. Alan Bates and 554 other sub-postmasters sued the Post Office collectively, pooling resources to engage forensic IT experts and sustain the litigation. The High Court’s findings on Horizon’s unreliability then fed into individual criminal appeals against the convictions that rested on Horizon evidence.
Why this template matters for Letby
The Letby case is a criminal case, not a civil group action. But the structural template is the same: collectively-resourced engagement of independent technical experts produces evidence that the original trial-level technical evidence was unreliable; that evidence then grounds appellate-level correction of the convictions.
The Letby analogue to the Bates 2019 judgment is not a single document but the accumulation of the Shoo Lee Panel report, the Joint Insulin Report, and the thirty-one-plus independent expert reports filed with the October 2025 CCRC application. Together they perform the same function: expose the original trial-level technical evidence as unreliable.
The Horizon timescale
The High Court judgment was in December 2019. The first Court of Appeal Horizon quashings were in December 2020 and onwards. Mass statutory exoneration followed in 2024 after the ITV drama. The full arc from technical-evidence judgment to mass exoneration was approximately five years — consistent with the timescale now applying to the Letby post-conviction process.
Read alongside
Sir Alan Bates — biography, The Post Office Horizon parallel, The Bates organisational template.