Criminal justice specialists call for new approach to identify emerging type of murderer with no prior convictions

The rise of “0 to 100” killers who go from watching torture, mutilation and beheading videos in their bedrooms to committing murder suggests there could be a link between extreme violence online and in real life, experts have said.

Criminal justice experts advocated a new approach, inspired by counter-terrorism, to identify an emerging type of murderer with no prior convictions, after cases such as Nicholas Prosper, who killed his mother and siblings and planned a primary school massacre.

Jonathan Hall, the government’s independent reviewer of terrorism legislation, said there was a “new threat cohort” combining terrorists who were radicalised online and those who had “gone down a rabbit hole and into a dark world”.

He said: “There are quite a lot of similarities: they are isolated loners, boys rather than girls; the internet is obviously central; quite a high proportion have neurodivergence.