Shannon McCoole ran one of the world’s largest dark web child abuse forums for around three years in the early 2010s. Key to McCoole’s eventual arrest and conviction was a piece of linguistic evidence: his frequent use of an unusual greeting term: “hiyas”. Investigators began searching the open internet for any markers of a similar linguistic style and a man was discovered using the giveaway greeting on a four-wheel drive discussion forum.

This linguistic evidence contributed to the identification, arrest and eventual conviction of McCoole, and agents were able to take over and run the forum – as him – for another six months, leading to the prosecution of hundreds of offenders and to the rescue of at least 85 child victims. In our latest Insights long read, a specialist in forensic linguistics examines how criminals give themselves away with the language they use.

Also today, new research is shedding fascinating light on why so-called “super-recognisers” are so much better than the rest of us at learning and remembering faces. The secret is focusing on lots of different points of the head, apparently, rather than simply staring into someone’s eyes.

For some, the hardest part of dying isn’t physical pain but the fear and sense of meaninglessness that accompanies it. A surprising treatment is now emerging to tackle this: psychedelic therapy.