Over the course of the film, the participants share not just their own hunches and suspicions about what happened that morning after Christmas, but also personal revelations about themselves and why the case resonates with them so deeply 20 years on.
Rest assured, nearly every conceivable theory is aired about what happened that night, ranging from the pedophile-intruder theories to abuse from those closer to home.
But the interviewees are not people who were directly involved in the case, although some had very tangential connections to the murder.
Ultimately, this evolves into a layered meditation on many things — crime and guilt, the exploitation of children and acting itself, to name just a few.
Working this time with American subjects, Green once again demonstrates a remarkable skill at drawing out her subjects, and they reward her with astonishing frankness in the interviews.