Krazov"Henry: Portrait of a Serial Killer" is a 1986's cult classic, which I was planning to see for years but kept forgetting. Now I remembered. It's very bleak, both thematically and visually, but it aged like fine wine. Due to budgetary constraints, most of the murders are shown as a detailed aftermath witch voice over of the murder. At the same time, scenes between Henry and Otis look like taken out of a sitcom. It could easily be an entry in the "Monster" anthology.
The drone music, combined with slow pacing, reminded me heavily of "Too Old To Die Young," which I am currently rewatching. This further shows that the movie was ahead of its time. And due to problems with rating and finding distribution, it was not until 1990 that many people could see it.
The director made a documentary before "Henry," and was gonna make another one, but the project collapsed. However, they had money in place, so they did this horror instead. Hence, I think, still docu vibes.