Jack O'Connell and Laura Dern have joined the cast of 'Trial By Fire'.

Jack OConnell

Jack OConnell

The 27-year-old 'Money Monster' actor is expected to play death row inmate Cameron Todd Willingham, who was convicted of the arson deaths of his own three children, while Dern, 50, will play Elizabeth Gilbert, a Texan housewife who sets out to get him released as she believes he has been falsely convicted.

The fact-based drama is being directed by Ed Zwick, who will also produce alongside Allyn Stewart & Kipp Nelson, and Alex Soros.

The filmmaker became fascinated by the tale when he first red David Gann's Polk Award-winning 2009 article in The New Yorker.

Zwick told Deadline: "From the moment I read David's brilliant reporting eight years ago, I have been possessed by this deeply moving, true story of injustice.

"David Grann has been one of these caught-in-the-roller-of-his-typewriter guys, quietly doing great work, and now all these wonderful things are happening with his stories being made into movies, from 'Killers of the Flower Moon' to the Robert Redford piece 'Old Man and the Gun'.

"The story was all there, with these two compelling characters. It is a remarkable story about people. Not just capital punishment but justice, which is a very important word right now. It has to have that pull to keep you pushing it up the hill this many years."

He also explained how it had been a struggle to get the movie together but is glad he kept pushing on with the project.

He said: "You've heard the story at the end of the year from everyone who gets up on that podium and talks about how hard it is.

"The good ones just take longer. I've been lucky enough to make movies I care about, and they become increasingly smaller targets that you hit at greater distances.

"Every year a couple manage to get through that crucible, but it's harder and harder. We got close a couple of times, but it came down to not being able to get the right actor or financier."

Production is set to start on October 2 in Atlanta.