Henninger Interactive Media announced that it has completed development of the dual-platform DVD version of “In the Grip of Evil”, a documentary film of the events that inspired the bestselling novel and movie “The Exorcist.”

“In the Grip of Evil” examines the complete case history of a 13-year-old boy in Mt. Rainier, Md. who seemed possessed by evil spirits that required an exorcism by Catholic priests.

The DVD shows the original production that first appeared on the Discovery Channel, including a re-enactment of the boy’s ordeal, as well as modern-day interviews with director William Friedkin, the priest who assisted the exorcist, clergymen and family who witnessed the paranormal event. Also included is commentary from a psychologist who attempts to decipher how modern science explains the only exorcism in modern times that has been extensively documented.

Taking up only one layer on the DVD disc, the viewer can listen to the diary of one of the priests as well as letters that were exchanged between the boy’s family, the church and others. These sources can also be printed and emailed, including the 90-page diary, which is intended to take advantage of a computer’s ability to scroll at much faster speeds than a video player. The e-commerce features allow viewers to visit Fox-Lorber’s Web site and see their catalog and other items.