First thing first. Objectively speaking, the movie is good on all technical levels. It's also a good re-telling of an historical fact.
I've read someone saying "the fire at the beggining is all fiction" this is not true. The fiction is that being the sheriff's family. But it's recorded "the Schafer community also believed Bannon murdered three children of another family he had worked for and burnt their house". You can even google this if you don't believe me.
So basically, the adaptation of real facts is not "fiction" in a way that deserves critique. All movies based on a true story "stretch" the truth a bit to fit it in the narrative. But overall, you can't tell me this movie doesn't actually attempt to depict the facts of the town with sincerity.
It should be told, that the movie doesn't take a strong stance regarding lynching and the death penalty. It just narrates the story, and shows you the grim reality of it all. There's no propaganda involved. It's very objective in this regard, which I respect.
It's not a movie I regret watching. But It's not a movie I'll rewatch a lot. Everything on it was good. But you can't the deny the movie is slow. Too slow for it's own good. The movie would've worked better with a runtime of 1h:30 minutes. Or as a miniseries divided into three weekly episodes. It's a good docu-film. It's just not a fun movie to watch. You can watch the first hour easily. But I had to watch the second hour the day after.