The US Killing star Mireille Enos has signed up to join Reese Witherspoon and Colin Firth in Devil's Knot.
Atom Egoyan is directing the gripping drama about the West Memphis 3 murder controversy, based on Mara Leveritt's 2003 book.
Mireille will play Vicki Hutcheson, Deadline.com reports, the mother of an eight-year-old boy who lives in a run-down area of West Memphis, who becomes an important witness in the murder trial, as the only link between two of the accused.
The film tells the story of Damien Echols, Jason Baldwin and Jessie Misskelley, who were tried in 1993 for the killing of three eight-year-old boys found hog-tied in a drainage ditch. They were sent to prison despite a lack of evidence and after years of appeals were released last year with 10-year suspended sentences. Baldwin and Misskelley were previously given life sentences, while Echols was on death row prior to their release.
Colin Firth is starring as Ron Lax, a private investigator who became the trio's first champion in 1993 when they were headed to trial, and offered them his services for free.
Reese will play Pam Hobbs, the mother of one of the murder victims who initially believes the trio killed her son, but is eventually persuaded that the three suspects are innocent.