A male director was initially attached to direct the film, but left the project after learning that Turner was planning on focusing on the women’s lives in prison. Harron had already read Turner’s script, and told her that she would gladly direct the film.

“I was reading [the script] as a friend as I was really intrigued when she said she was going to include the perspective of the women in prison three years after the murders and what happened to them, because no one has covered that,” Harron told The Upcoming.

“I said I’ll make it, I love the women-in-prison stuff, and I find Karlene a really wonderful character.”

However, Harron stressed that she wasn’t interested in advocating for the women featured in the film. “For everybody looking at the movie, you don’t want just to stereotype them as monsters and something other to us,” she said. “I wanted to look at them and see my common humanity with them. But at the same time, I wanted the audience to both have sympathy and face the reality [of what they did].”

Charlie Says is set for release in UK cinemas on 17 May, 2019.

This film about the Manson Family women promises to explore cult psychology