he thought he could get away with it, then the police found his Snapchat.

Originally broadcast on 11th November 2025. If you or anyone you know has been affected by this video, details of organisations offering information and support are available at BBC Action Line: https://www.bbc.co.uk/actionline/ This is the story of how one teenager abused thousands of children from behind a screen. Alexander McCartney used Snapchat, fake profiles and catfishing to target victims across the world. When a 12-year-old girl in Scotland reported what had happened to her, police began tracing the messages back to him. This video follows the start of the investigation, and the moment McCartney was arrested. Head to BBC iPlayer to watch the full episode, from the series Teen Predator/Online Killer. Subscribe: youtube.com/@bbcdeepwatch?sub_confirmation=1 BBC deepwatch is powered by BBC Three: https://www.bbc.co.uk/tv/bbcthree For full accessibility, including accurate subtitles, you can watch the fully accessible version of this video on BBC iPlayer. #catfish #truecrimedocumentary #snapchat