i don't know when that was but in keeping with Morrissey's character, I'm guessing it was pre-2010 at least
Turning it into a kind of murder mystery/thriller from the POV of any Native character would likely ultimately turn it into the kind of tantalizing true crime story that Scorsese is critiquing with the radio play at the end
According to the author of the book. Every single white person living in that area was complicit. He said something like " I went my research thinking it was going to be a 'who did it?' and what I quickly discovered was that it was a 'who didn't do it?' "