Want horror in the court?

“THE Exorcism of Emily Rose,” which hits theaters Friday, owes an unmistakable debt to 1973’s epochal horror classic, “The Exorcist.” In both films, an impressionable young woman becomes Satan’s unwitting vessel and must be purged by a determined priest.

While the earlier film spawned an entire subgenre of to-hell-with-the-devil-themed horror, “Emily Rose” attempts to stand out in a copycat genre: It’s the first horror movie/courtroom drama hybrid boasting Big Ideas, art-house movie stars and a red state-friendly religious agenda.

The determined priest in this case, played by Tom Wilkinson, is accused of negligent homicide after his attempt at demonic cleansing culminates in Emily Rose’s death. Refusing to cop a plea, he maintains that he was simply obeying God’s will, and over the course of his trial, details of the exorcism are revealed in flashback. It’s a heavily fictionalized version of the controversial exorcism-induced demise of Bavarian college student Anneliese Michel in Germany in 1976.

Campbell Scott portrays a punctilious state prosecutor and Laura Linney plays the priest’s ambitious defense attorney whose efforts to limit his culpability end up underscoring much bigger issues.

The lawyers’ closing arguments serve, in effect, as a referendum on spiritual faith and the existence of God.

According to “Emily Rose’s” director and co-writer, Scott Derrickson, the scary-movie genre provided an ideal medium for posing fundamental philosophical questions.

“What’s interesting to me about the horror genre is that it’s so ripe for spiritual and religious content,” he said by telephone from the Venice Film Festival, where “Emily Rose” premiered last week. “It’s the one genre that takes good and evil the most seriously. There’s always a moral passion at the center of a good scary movie.”

The director said he was inspired by Dante’s “Inferno” and Christian novelist C.S. Lewis’ “The Screwtape Letters” to create “something with depth, something horrific and gothic that wouldn’t be considered exploitation.”

However, the filmmakers said they lifted the idea to use the priest’s trial as a narrative framing device directly from “The Exorcism of Anneliese Michel,” the nonfiction book that served as the basis for the script.

“We were struck that the courtroom is such a great theater for ideas -- and that we couldn’t think of a film that had combined the horror and courtroom genres,” co-writer Paul Harris Boardman said. “We thought we could really develop something provocative out of that: structure the movie with multiple points of view like ‘Rashomon’ and weave the narrative in and out of it.”

Although horror films are popular -- and continue to appear in the box-office top-10 almost every other week -- horror is not, dollar for dollar, the hot genre it was a year ago.

“This year there has been a bit of a slowdown,” said Paul Degarabedian, president of Exhibitor Relations. “In 2004, 19 so-called scary movies generated just over a billion dollars. This year, we’ve had 20 of these movies generate $580 million. There has been a bit of audience fatigue.”

With that in mind, “Emily Rose,” with its $19-million budget and moody cinematography by Tom Stern (director of photography on Clint Eastwood’s “Mystic River”) can be viewed as an experiment in expanding the genre’s strict conventions.

THE film’s distributor, Screen Gems, is hedging its bets that Wilkinson, Linney and Shohreh Aghdashloo (who plays an exorcism anthropologist in the movie) will distinguish “Emily Rose” as something more than a big, dumb horror film and appeal to an adult audience in search of intelligent thrills.

“Our movie has three Academy Award nominees -- that’s not by accident,” said Clint Culpepper, Screen Gems’ president and the film’s executive producer.

“I never saw this as a ‘horror movie,’ ” he continued. “I always saw this as an art-house treatment of a horrible story.”

Culpepper also expressed optimism that the film will attract moviegoers from across America’s cultural divide.

“There’s a huge faction in this country that we call the red states who I think will respond to the fact that [Emily Rose] made a choice based on her belief and on her faith,” he said.

Derrickson, who describes himself as a practicing Christian, however, said he and Boardman were wary of appearing didactic and made a specific effort to avoid any religious agenda.

“Paul and I felt that would be an opportunity to get at very interesting religious and spiritual subject matter that was not preachy or set in a particular point of view,” he said.

Boardman, who describes himself as an agnostic, said his 10-year creative relationship with Derrickson was predicated, in part, on balancing their secular and religious ideals.

“We joke that we have a Scully-Mulder approach,” he said, invoking the protagonists of TV’s “The X-Files.”

“Religion has become so polarizing in America. It’s either ‘You’re with us or you’re against us.’ This film is about that. We try to meet in the middle.”