UK Plans to Use AI to Review Digital Evidence in Criminal Cases

LONDON — Police officers could use artificial intelligence to review and summarise evidence under proposed changes to the criminal-disclosure system announced by the UK Government.

Current disclosure guidance was introduced in 1996, before smartphones, social-media platforms and cloud-storage services transformed the volume of material produced during criminal investigations. Some cases now involve data equivalent to more than 500,000 electronic books, while an average fraud investigation may contain more than four million documents.

The Home Office has accepted key recommendations from an independent review led by Jonathan Fisher KC, including proposed legislation allowing AI to assist with evidence review. Police currently identify, process and summarise files that may be relevant to an investigation or later court proceedings.

Under the proposals, technology could help investigators identify, sort and compile millions of files, including emails, messages, videos, phone records and cloud-storage material. PoliceAI, the National Centre for Police AI, will pilot tools capable of producing automated summaries, with wider expansion across police forces considered from 2027.

PoliceAI is backed by £75 million in government funding. Ministers estimate that its broader work could free approximately six million hours of police time each year by 2028, described as equivalent to the work of around 3,000 officers. These figures are government projections and will need to be tested against actual operational results.

A productivity review found that officers spent approximately 532,000 hours during 2022–23 conducting disclosure work and preparing case files in matters that were later assessed by prosecutors as requiring no further action.

Disclosure is not merely an administrative process. It is an essential legal safeguard requiring investigators and prosecutors to identify material that may undermine the prosecution case or assist the defence.

AI systems may struggle with context, coded language, sarcasm, low-quality recordings, multilingual material or files whose significance becomes apparent only when combined with other evidence. An inaccurate summary or missed document could affect a defendant's right to a fair trial.

The Government says technology will support rather than replace professional judgement. A national governance forum involving police, prosecutors, the judiciary and government will oversee emerging disclosure technologies and related safeguards.

Responsible implementation should include independent accuracy testing, audit trails, human review and clear procedures allowing defence lawyers to question how automated systems were used.

AI may help investigators cope with the unprecedented volume of digital material in modern cases. Public confidence will depend on whether efficiency is achieved without weakening transparency, accountability or legal rights.