It takes a lot of chutzpah to include the word “exorcism” in the title of a new horror movie.

“The Exorcist” (1973) is widely regarded as the best and scariest horror flick ever made. Other than the film’s various sequels, no other mainstream movie has attempted to commandeer the term.

But instead of “The Haunting of …” or “The Possession of …” the filmmakers involved in a new shocker have brazenly put forth “The Exorcism of Emily Rose.”

Surprisingly, the project earns the right to the title.

To be fair, “Emily Rose” is not exactly a horror movie. It’s a hard-to-classify effort that is equally composed of courtroom thriller and religious allegory.

But when it’s scary, it’s extra scary. Nails-in-the-armrest scary.

In fact, there is a shot in “Emily Rose” that is probably the most disturbing thing a viewer will see all year – even worse than the chest-waxing scene in “The 40-Year-Old Virgin.”

Laura Linney, left, portrays an agnostic lawyer who defends a Catholic priest (Tom Wilkinson) from charges that an exorcism he performed on a college student resulted in her death in The

It involves no visual trickery, no sound effects and no gory makeup. It’s accomplished merely by positioning the disturbed girl’s body in relation to a character who shares the audience’s point of view.

We never actually meet Emily (newcomer Jennifer Carpenter) except in flashback.

As the film begins, Father Richard Moore (Tom Wilkinson) stands accused of negligent homicide in the case of Emily. Her pious family believed the college student was possessed, and when the medical community couldn’t help, they called in the family priest to perform an exorcism. The ritual failed, and Emily eventually succumbed to a combination of malnutrition and injuries.

Hotshot lawyer Erin Bruner (Laura Linney) is brought in to defend Father Moore. Although an agnostic, Erin is excited for the opportunity – not just because it may land her a full partnership in the firm, but because she believes the cleric might just be innocent, and at her last high-profile trial she convinced a jury to let a murderer go free.

“God knows I have my own demons,” she confesses.

• Audio interviews with Jennifer Carpenter and Laura Linney
• Jennifer Carpenter: Was there any trickery to help you achieve the “possessed” voice?
• Laura Linney: Did you do any research into the rite of exorcism
• Performing an ‘Exorcism’ (09-09-05)

The state counters with a well-respected Methodist prosecutor (Campbell Scott) who is “no choirboy in the courtroom.” The trial becomes a battle between religion and science (was Emily just an epileptic psychotic?), and faith versus fact.

The ads for “Emily Rose” trumpet that it’s based on a true story. The outline mirrors the case of Anneliese Michel, a German girl who endured a similar experience during the 1970s, which resulted in her death and the prosecution of those who performed the exorcism.

But this is Hollywood, and the rest of the screenplay is plain old fiction. There’s no reason to take any of the picture at face value other than as a well-crafted, often thought-provoking exercise.

Writer-director Scott Derrickson and writer-producer Paul Harris Boardman cast the film with a combination of Oscar-caliber vets, but it’s the formidable young Carpenter who makes the most impression. While Linda Blair in “The Exorcist” supplies innocence and evil, Carpenter’s work is far more subtle and subjective. Alternate flashbacks suggest she is suffering medical afflictions; other times there is no doubt she is being manipulated by demons.

The movie juggles these areas with skill, except for two notable exceptions. The fate of the defense’s “star witness” is telegraphed in such a clumsy, melodramatic way that it feels spliced in from another movie.

And while it’s conceptually fine to show demonic visions from Emily’s point of view – if she’s psychotic, she could be seeing anything – it doesn’t makes sense for Father Moore to witness them also. His sanity is not in question. If it’s vividly clear that the supernatural is at work, then the duality of the film’s central mystery is compromised.

It’s like inserting a brief cameo into “The Blair Witch Project” of the actual hag performing magic spells.

Too bad the filmmakers of this ambitious horror-drama couldn’t have exorcised more sequences in the editing room.