CPS trials AI tool to transform routine correspondence

The Crown Prosecution Service (CPS) has run a pilot of an AI-powered tool designed to draft routine correspondence, marking a significant step in its drive to improve efficiency and reduce administrative burden.

The Correspondence Drafting Tool, developed with NTT Data UK, uses Microsoft’s GPT-4 model combined with rule-based templates to generate first drafts of letters and emails. Drawing on information from the CPS’s case management system, it produces plain-English text that staff can review, edit, and approve before sending.

The pilot is currently in a beta phase, involving around 30 trained CPS staff. Officials say the tool aims to improve the quality and consistency of communications, minimise errors caused by manual copying and pasting, and save time for prosecutors and administrators.

The CPS emphasises that the system does not make decisions or take actions without human involvement. Every AI-generated draft is reviewed by a member of staff, who remains responsible for the final content.

To reduce the risk of inaccurate or misleading outputs, the CPS has put in place robust controls, including user training, regular auditing, and a multi-layered review process. Generated text is deleted once correspondence is complete, and no CPS data has been used to train the underlying model.

This latest initiative follows a successful trial of Microsoft Copilot in 2024, in which more than 400 CPS staff used generative AI to summarise case notes, prepare internal documents, and analyse data. Lessons from that trial informed the design of the correspondence tool and its human-in-the-loop safeguards.

By publishing full details of the project in the government’s Algorithmic Transparency Record, the CPS aims to set a standard for openness and accountability in public sector AI adoption.