Court of Appeal urges AI regulation in criminal courts over ‘witness coaching’

Court of Appeal judges have called for the Criminal Procedure Rule Committee, prosecutors and police chiefs to ‘address and regulate the use of AI in criminal proceedings’ after a rape trial collapsed over the witness's use of the technology. 

In Rex v FGD, Lady Justice May, Mr Justice Griffiths and His Honour Judge Picton allowed the prosecution appeal against  Recorder Hay’s ruling part-way through a rape trial at Lewes Crown Court. The ruling stayed proceedings after the complainant was found to have used AI to help prepare for court.

Saying the case was ‘unlikely to be an isolated example’, the appeal judges added: ‘We suggest that, to the extent that they are not already doing so, the National Police Chiefs Council, the Crown Prosecution Service and the Criminal Procedure Rules [sic] Committee may wish to consider how to address and regulate the use of AI in criminal proceedings.’

The appeal proceeded on the basis that the documents – found on the complainant’s phone after a ‘broad and intrusive’ search of it – were generated by AI in response to prompts from the complainant.

‘Witness training is forbidden in all jurisdictions,’ the judgment said. However, it noted that much of the complainant’s evidence was ‘uncontaminated’ as her evidence-in-chief was pre-recorded shortly after she made a report to police following the alleged incident.

Lady Justice May, in lead judgment, said: ‘This is precisely the kind of case where the trial process would be well able to deal with any potential prejudice ... arising from [the complainant's] resort to AI in advance of cross-examination.’

She added that one danger surrounding witness training is that it is conducted behind closed doors and not fully recorded, so that it cannot be discovered precisely what has been said, or suggested, to the witness. ‘By contrast, here, all that the AI “coach” provided to C was fully recorded and could be placed in its entirety before the jury, or summarised by agreement and put into agreed facts.’

The recorder was found to have ‘erred in concluding that [the defendant] could not have a fair trial’, the Court of Appeal said. ‘In future we would encourage counsel on both sides when dealing with an application to stay for abuse explicitly to raise and explore all the ways in which the trial process could deal with any potential prejudice so that the trial judge is able to consider and deal with each separately, when ruling on the issue.’

The appeal was allowed and the recorder’s ruling reversed. A retrial was ordered to be listed ‘at the earliest opportunity’.