https://deadline.com/2017/04/martin-scorsese-leonardo-dicaprio-eric-roth-killers-of-the-flower-moon-movie-david-grann-book-1202073488/
https://www.thesun.co.uk/tvandshowbiz/7581191/killers-of-the-flower-moon-leonardo-di-caprio-david-grann-book/
We should know more towards the end of the year or early 2019 who else is in the cast.
https://www.youtube.com/watch?v=AKjvrSS-UXU&list=PL0LKIR5xtjNF3mz1-a00FDLj3T4MALWbH&index=3&t=0s
I have been reading this book as well; I am 12% (1/8) Native American (great-grandmother 100%). I saw a history news item about this event and have been reading the true history of the killings. In WI, I have been researching the Blackhawk Wars, the killing site is very near where I live. It lead me to the Osage story.