There are plenty of things one simply cannot do in two hours; if Devil's Knot is any indication, one cannot try to tell the story of the trial of the West Memphis Three in two hours. Paul Harris Boardman and Scott Derrickson's script seems to do quite a bit well–for the first third of the film, the horrific nature of the crimes has the film sympathizing with the police officers (Robert Baker in particular), only to later reveal incompetence and corruption on these characters' parts.
Then, once the script's obviously manipulative nature becomes clear, it's hard to take Knot seriously. The deception makes little sense, since the film's written for people familiar with the case (as there's no explanation why Damien Echols isn't executed at the end).
As for second-billed Reese Witherspoon, who plays a grieving mother looking for the truth, her arc's incompetently handled. At least Colin Firth doesn't have an arc or character development. It may very well be historically accurate, but it's far from dramatic.
There are some excellent performances. Kevin Durand and Alessandro Nivola are both good as suspicious fathers. Amy Ryan has a nice scene. Firth isn't bad. Witherspoon eventually gets a little better–but it's too little too late. Much of the supporting cast and some of the principals are weak. Especially James Hamrick as Echols.
Mychael Danna's score is manipulative and derivative. Director Egoyan does an insincere job. It's tepid, vaguely incompetent and Oscar-desperate.
Its compelling nature has nothing to do with the filmmaking.
Directed by Atom Egoyan; screenplay by Paul Harris Boardman and Scott Derrickson, based on the book by Mara Leveritt; director of photography, Paul Sarossy; edited by Susan Shipton; music by Mychael Danna; production designer, Phillip Barker; produced by Elizabeth Fowler, Richard Saperstein, Clark Peterson, Christopher Woodrow and Boardman; released by Image Entertainment.
Starring Colin Firth (Ron Lax), Reese Witherspoon (Pam Hobbs), Dane DeHaan (Chris Morgan), Mireille Enos (Vicki Hutcheson), Bruce Greenwood (Judge David Burnett), Elias Koteas (Jerry Driver), Stephen Moyer (John Fogleman), Alessandro Nivola (Terry Hobbs), Amy Ryan (Margaret Lax), Robert Baker (Det. Bryn Ridge), Kevin Durand (John Mark Byers), Michael Gladis (Dan Stidham), James Hamrick (Damien Echols), Martin Henderson (Brent Davis), Kristopher Higgins (Jessie Misskelley Jr.), Brian Howe (Detective McDonough), Matt Letscher (Paul Ford), Seth Meriwether (Jason Baldwin), Rex Linn (Inspector Gary Gitchell), Kristoffer Polaha (Val Price) and Collette Wolfe (Glori Shettles).