The Killing star Mireille Enos has joined Reese Witherspoon and Colin Firth in Devil’s Knot, the Atom Egoyan-directed drama about the West Memphis 3. Enos will play Vicki Hutcheson, the mother of an 8-year-old boy who lives in a run-down house in West Memphis. She becomes an important witness in the murder trial of Damien Echols, Jason Baldwin and Jessie Misskelley for the killing of three 8-year-old boys found hog-tied in a drainage ditch. Hutcheson, it becomes apparent to investigators, could be the only link between Echols and Misskelley.

As Deadline revealed just after the West Memphis 3 murder defendants were released from prison last summer, The Sweet Hereafter and Chloe director Egoyan came aboard to direct a script that was originally written by Scott Derrickson and Paul Boardman, the team behind The Exorcism Of Emily Rose.

Firth will play Ron Lax, a private investigator who was the first pro bono supporter of the defendants as they headed to trial in 1993. Lax built one of the most prominent private investigative firms in the Southeast, and offered his services for free to the defendants, who at the time were reviled because of the heinous nature of the crime and the sensationalized reports about devil worship and ritualistic sacrifice. All of that was later proven to be unfounded, after the West Memphis 3 were convicted despite a total absence of physical evidence. Witherspoon is playing Pam Hobbs, the mother of Steven Branch, one of the victims. She initially believed the trio murdered her son and the other two boys but became persuaded they were wrongly accused. An upcoming documentary casts suspicion on her ex-husband Terry Hobbs, who was Steven Branch’s stepfather and who has denied any wrongdoing.

The script is based on investigative reporter Mara Leveritt’s 2003 book Devil’s Knot: The True Story of the West Memphis Three, an in-depth chronicle of the sensationalized trials. Elizabeth Fowler, Richard Saperstein, Clark Peterson, Christopher Woodrow and Paul Boardman are producing.

Enos was nominated for a Golden Globe and Emmy for her role as detective Sarah Linden in AMC’s ‘The Killing.” She next stars with Josh Brolin, Sean Penn and Ryan Gosling in Gangster Squad, which Warner Bros releases September 7, and alongside Brad Pitt in World War Z, which gets released next summer. She’s repped by CAA and Gartner/Green Entertainment.

– Deadline.com