Reese Witherspoon, now 35, has signed on for director Atom Egoyan's serious drama Devil's Knot. Based on Mara Leveritt's book of the same name, the story recounts the murder trial of the West Memphis Three.

Witherspoon was cast as Pam Hobbs, the mother of one of the victims. According to The Huffington Post, no other stars are attached to the film yet.

Devil's Knot is scheduled to release in late 2012.

The case of the three men accused of murdering three 8-year-old Boy Scouts in West Memphis, Arkansas in 1993 held the attention of the country for 18 years. The men were released in August after spending 17 years in prison due to new DNA results that proved that DNA from the crime scene did not match any of the three men.

A pair of HBO documentaries, Paradise Lost and Paradise Lost 2: Revelations, depict the controversial convictions and generated the nickname West Memphis Three.

Numerous celebrities, including Johnny Deep, Pearl Jam's Eddie Vedder and director Peter Jackson, supported the three men's innocence.

I firmly believe Damien Echols, Jason Baldwin and Jessie Misskelley are totally innocent, Depp told CBS' 48 Hours Mystery before their release. It was a need for swift justice to placate the community.

The seriousness of this film will be a change for Witherspoon, whose latest film, This Means War, is a romantic comedy about two CIA agents who discover they are both dating Witherspoon. This Means War will release Feb. 17.