Subject: Fred Leuchter, constructor of execution equipment
I don't know how Errol Morris finds these fascinating subjects, and I know even less about how he gets them to appear in his documentaries. The story of Fred Leuchter is a great study in epistemology - how what we know can very often mislead us if there's one key fact we're omitting. We can be even more misled if we are purporting to use rigor - our rigor may lead us right off a logical cliff.
I won't spoil what this documentary eventually turns into, but it's completely unbelievable. I wish I hadn't spoiled it for myself by looking at the Netflix movie jacket. A must-see for fans of Morris.