TL;DR

A senior crown prosecutor relied on a Court of Appeal authority that does not exist when explaining a decision to prosecute a boy in the youth court. In a judgment dated 29 October, the High Court called her explanation “unsatisfactory” but said it did not change the outcome. The Guardian reported on 3 November that it understands the citation came from an AI summary in an internet search; the judgment itself does not mention AI.

The judgment, LYC v Director of Public Prosecutions, came from Lord Justice Holgate, sitting with Mr Justice Wall. The prosecution’s paperwork pointed three times to R v J, cited as a 2024 Court of Appeal decision, and all sides now agree no such decision exists. In a 15 October statement, the prosecutor said she had made a mistake and meant the 2009 House of Lords case R v JTB.

The claimant’s lawyers argued that the propositions drawn from it were absent from that decision and wrong in law. The court rejected that ground as unarguable. Its reasoning turned on whether the principles applied were sound, not on where the citation came from.

The CPS has not described this as an AI error in terms. It told the Guardian that it “identified an error had occurred from conducting legal research using the internet”, that it reviewed whether other cases were affected, and that case law “must be cited from trusted legal sources”. It also says its AI policy requires human checks for accuracy.

The AI attribution rests on the Guardian’s own understanding. Brian Flanagan, a Maynooth University law academic who studies judges’ use of AI, told the paper: “This was used as a legal source to argue for the prosecution of a child and that legal source doesn’t exist: that’s a serious failure.”

A second CPS case

The Guardian calls this the service’s second known case, after the extradition filings we covered in July. According to the paper, the CPS concluded then that “the risk of recurrence was low”. The latest incident takes a UK tracker kept by Doughty Street barrister Matthew Lee to 101 entries, which logs errors whether confirmed, suspected or disputed. Lee warned that this may be the “tip of the iceberg”, because many lower court decisions go unpublished.

Looking Forward

The Guardian says the boy’s trial was listed for the days following its report, so the underlying case remains live. In our view, the wider point concerns search tools. A lawyer need not open a chatbot to meet this problem, if an AI summary sits at the top of a results page. The Civil Justice Council’s recent report on AI in court documents is one place that debate continues, and verification rules written for deliberate AI use may need to reach ordinary searching as well.

Share this article