True-crime fans are banding together online to try to solve cases

It is 9am on a Sunday and Liz is trying to figure out who did it. Specifically: who killed this guy splayed across the floor? In her day job Liz is a massage therapist, but today she is a homicide detective—or rather she is cosplaying one. Wearing blue latex gloves she prods a blood-soaked mannequin by her feet, part of a crime-scene simulation at CrimeCon, a convention for true-crime fans. Liz came to learn from the experts. They start with the basics: it is blood spatter, not splatter.