It’s been 22 years since the cops found all those murdered, molested, cut-up corpses in a factory worker’s tiny Milwaukee apartment. Does this particular serial killer still hold much fascination for America? Does he for filmmaker Chris James Thompson? Hard to say, with only The Jeffrey Dahmer Files to go on. Thompson’s reticently experimental documentary seems fixed on the banality-of-evil angle, and apparently unconcerned with one ironic consequence of its presentation: the evil of banality. The scenes Thompson elects to stage are deliberately quotidian and at best only vaguely depraved, as when the flat-affect killer acquires his body-disposal barrel and lugs it awkwardly onto a city bus, or just sits alone on his couch, beer in hand, staring off into space. These could be Coen brothers moments, had they more dramatic shape, but at least Thompson seems on guard against trivialization. Dutifully, he also gathers testimony. The medical examiner explains how, for want of “a docile sex partner,” Dahmer drilled a hole in a living person’s head. The lead detective recounts lending his son’s clothes to the killer for a court appearance. A dismayed neighbor says she cried when everyone else later cheered the news of Dahmer’s death. Otherwise, Thompson relies on us to catalyze his chronicle and fill in its blanks with our own queasy retrospective awareness. That may be prudent given so much pre-existing Dahmer media lore, but this film still feels abbreviated, as if glumly aware of how little insight it really has to add.