Actress Reese Witherspoon has joined the cast of Devil's Knot for director Atom Egoyan.

Reese Witherspoon will play Pam Hobbs, the mother of a West Memphis 3 murder victim, who initially believes the trio committed the crime, but eventually is persuaded that they are innocent. The West Memphis 3 - Damien Wayne Echols, Jason Baldwin and Jessie Miskelly - were exonerated from the 1993 murders in August, after spending nearly two decades in prison.

Atom Egoyan is directing from a screenplay by Paul Harris Boardman and Scott Derrickson, which is adapted from Mara Leveritt's 2003 non-fiction book.

The project is seeking independent financing, with production slated to begin this coming summer.