John Zaffis has over forty years of experience studying and investigating the paranormal. He has had the opportunity to work for and with his aunt and uncle, Ed and Lorraine Warren. This sent John beyond looking for ghosts and hauntings and into studying demonology under the Warrens. This led into John's involvement with cases of possession and exorcism, which gave him the opportunity to work with prominent exorcists in this field, including Roman Catholic priests, monks, Buddhists, rabbis and ministers. John has assisted and worked with well-known exorcists Bishop Robert McKenna, Father Malachi Martin, and the Reverend Jun.
His research has taken him throughout the United States, Canada, England and Scotland covering several thousands of cases. Through hands on investigating with other investigators and clergy, he has obtained a great deal of knowledge and understanding of the paranormal and is considered one of the foremost authorities in the field today.