AI proliferation is reshaping serious online criminality. While the use of AI by criminals remains at an early stage, there is widespread evidence emerging of a substantial acceleration in AI-enabled crime, particularly evident in areas such as financial crime, child sexual abuse material, phishing and romance scams. Criminal groups benefit from AI’s ability to automate and rapidly scale the volume of their activities, augment existing online crime types and exploit people’s psychological vulnerabilities. This report aims to equip the UK national security and law enforcement communities with the tools to plan and better position themselves to respond to novel threats over the next five years. That process will require more effective coordination and targeting of resources, and more rapid adoption of AI itself. It should start with the creation of a new AI Crime Taskforce within the National Crime Agency – which would collate data across UK law enforcement to monitor and log criminal groups’ use of AI, working with national security and industry partners on strategies to raise barriers to criminal adoption.