The Court of Appeal has called for the introduction of clear guidance on the use of artificial intelligence (AI) in criminal proceedings after a rape trial was halted because a complainant used AI while preparing to give evidence.
In the case of R v FGD, the Court of Appeal overturned a ruling made by Lewes Crown Court, where proceedings had been stayed after concerns were raised about the complainant’s use of AI-generated material before the trial. Lady Justice May, Mr Justice Griffiths and His Honour Judge Picton concluded that the defendant could still receive a fair trial and allowed the prosecution’s appeal.
The judges acknowledged that the issue is unlikely to be an isolated incident and suggested that the Criminal Procedure Rule Committee, the Crown Prosecution Service (CPS), and the National Police Chiefs’ Council (NPCC) consider introducing rules to regulate the use of AI in criminal cases as the technology becomes increasingly accessible.
The appeal was heard on the basis that documents discovered on the complainant’s mobile phone had been produced by AI in response to prompts entered by the witness. While the court reaffirmed that witness coaching is prohibited in all jurisdictions, it distinguished this situation from traditional coaching because every AI interaction had been recorded and could be fully disclosed during the trial.
Lady Justice May noted that a significant portion of the complainant’s evidence had already been recorded shortly after the alleged incident through pre-recorded evidence-in-chief, meaning it remained unaffected by the later use of AI. She added that any potential prejudice arising from the AI-generated material could have been addressed through the normal trial process, including cross-examination and judicial directions.
The Court also observed that one of the main concerns surrounding witness coaching is that it often takes place privately, making it difficult to determine what advice was given. In contrast, AI-generated responses leave a complete record that can be examined by both parties and presented to the jury if necessary.
The judges found that the trial judge had been wrong to conclude that the defendant could not receive a fair trial. They encouraged prosecutors and defence counsel in future cases to explore all available measures for managing any concerns relating to AI before asking the court to stay proceedings.
As a result, the Court of Appeal allowed the prosecution’s appeal, overturned the earlier ruling, and ordered that the case be listed for retrial at the earliest opportunity.
The decision highlights the growing challenges that artificial intelligence presents to the criminal justice system and signals that formal regulation may soon become necessary to ensure fairness, transparency, and confidence in criminal proceedings.
