Complainant used AI for trial prep — rape case halted

Controversial use: A complex rape trial held in southern Britain was abruptly halted after it emerged that the complainant had used an AI-based chatbot to prepare and engineer her answers for cross-examination, as reported yesterday (Monday) in the British Telegraph.

The case began when the defendant, designated as R, was accused of committing rape against a victim designated as C after she had consumed a large amount of alcohol and drugs. The two had previously been in a consensual relationship, but C had ended it several weeks before the incident. As part of the cross-examination, C, the sole prosecution witness, was questioned at length on issues including her location and conduct that evening.

The mistake that revealed the correspondence

The dramatic plot twist occurred at the initiative of the complainant herself. After completing the cross-examination, C asked to submit screenshots from her personal mobile phone to the court to strengthen her version of the answers. However, the submission of evidence led to a legal demand for the handover of the entire device's data to the defense team — and a surprise awaited them. Upon checking the device, detailed logs of lengthy conversations the complainant had held with an AI chatbot were discovered. The logs were divided into defined topics, including: 'About what happened that night', 'About consent and capacity', 'About physical evidence', and 'About your behavior after'.

Improper 'witness coaching'

Following the exposure, R's defense attorney argued that a fair trial could no longer be held, as it was impossible to know to what extent the complainant's testimony had been influenced by the chatbot. The Court of Appeal partially accepted the argument and ruled that this was the prohibited practice of 'witness coaching':

«All witnesses, whether for the prosecution or the defense, must be strictly kept away from using artificial intelligence to prepare for giving testimony.»

The judges further stated, hinting at the complainant:

«An honest witness might change the emphasis in their testimony to align it with what they perceive as a more accurate, or simply more correct, memory of events. In contrast, a lying witness will think very quickly about how to 'improve' their testimony.»

In Britain, there is a strict prohibition on 'witness coaching' for fear that memory will be contaminated. The rules allow lawyers to prepare witnesses through mock trials, but strictly prohibit shaping evidence or rehearsing the content of the testimony itself — a rule established back in 2004. The local court in Lewes believed the case should be dismissed entirely, but the Court of Appeal ultimately ordered that a retrial be scheduled at the earliest possible date.