After premiering at Sundance in January, the film has made the round of global festivals, and was screening at the London Film Festival just as it opened in US cinemas. This is the true story of Christine Chubbuck, a 29-year-old journalist at a TV station in Florida who in 1974 shot herself in the head during a live newscast. Since then, it's been revealed that she suffered from a variety of mental health issues.

Rebecca Hall stars as Christine Chubbuck in the new film ChristineRebecca Hall stars as Christine Chubbuck in the new film Christine

Hall says that despite the controversy, she was drawn to writer Craig Shilowich and director Antonio Campos' sensitive take on the story. "I'd not heard of Christine Chubbuck," Hall says. "When I read the synopsis, I was like, 'Why? Why do this?' I got kind of angry about it. And then I realised actually that if a film doesn't grapple with this in a way that is compassionate and universal, then the thing she did is left to become reductive horror. Because that's how she appears on the internet, on every top ten most shocking list."

To play the role, Hall had to get inside Christine's head and understand her motivations. "There's a person behind this," she says. "We all know what it is to be stymied at work. We all know what it feels like to get depressed from time to time. We all know what it feels like to be unloved. It's really hard for us to admit that were it not for circumstances that are completely arbitrary - gender, gender in time and place, social context, brain chemistry - we might all be capable of going over the edge. I don't mean in the way she did, specifically."

Hall Believes that the film makes Christine almost frighteningly easy to relate to. "A lot of people go through life trying to perform 'normalcy', and I think you can relate to that," she says. "She is someone who, despite her illness, is trying to live a noble life. But then she decides to do something incredibly violent."

The actress was determined to avoid turning Christine into a monster. "The question is how anyone becomes radicalised," Hall says. "I don't think it's helpful to put them all in a box and say people are evil and freaks because they have gotten to the point where they have fallen out of the community of what it is to be a human being. I think it's possible to bring humanity to everyone."