In October, 1993, William Roll conducted a preliminary investigation of two Scandinavian castles, both with long histories of hauntings. One was Dragsholm Castle, about an hour and a half drive from Copenhagen, Denmark, and the second was Engsö Castle, about a two hour drive from Stockholm, Sweden. Both castles are hundreds of years old.
Roll was interested in reports of hauntings at these sites because the present witnesses seemed to be credible and because the structures both have extensive granite foundations. Dragsholm Castle is partially built out of large granite boulders, and Engsö Castle is built directly on top of a large granite outcropping. Granite has been linked to psychic-type experiences in sacred sites, perhaps because it is a source of ionizing radiation, which may directly stimulate unusual physiological states which in turn cause witnesses to perceive apparitions (Devereux, 1990; Roney-Dougal, 1991). Another possibility is that geological stressors on granite cause large-scale piezo-electric effects which creates localized, high-intensity electromagnetic fields; these in may affect witnesses' neurological states and induce apparitional experiences (Persinger, 1993).
In July, 1994, the authors were invited to conduct a second investigation at these castles. Accompanying us on this trip were Dr. Raymond Moody and his spouse, Cheryl Moody. Raymond Moody was asked to participate because he had seen an apparition in a previous haunting case investigated by Roll.
Radin's primary role in the investigation was to use portable survey equipment [footnote -> link?: Equipment included an EMDEX-C electromagnetic field monitor, manufactured by Electric Field Measurements, and kindly donated to William Roll by the Mind Science Foundation, San Antonio, TX; RM-60 radiation monitor, made by Aware Electronics.] to measure electric fields, magnetic fields, and background radiation in the castles to search for anomalous readings that might correspond to traditional haunting locations, and to act as a 'sensitive' to see if he could subjectively detect anything anomalous about these sites. In both cases, before learning anything about the histories of the sites, Radin completed the physical and subjective surveys so he was not biased in any way by prior knowledge.
Aside from participating in the instrumental investigation, Roll's role was to conduct extensive interviews with castle staff and other people who witnessed apparitions, had other unusual experiences, or who knew the history of the site. Raymond Moody's role was to act as a 'sensitive'.