Paranormal researcher and nephew of Ed and Lorraine Warren, John Zaffis, shared insights and experiences he has accumulated in his 30 years of dealing with hauntings, possessions, and exorcisms.One of the most dramatic cases, he said, was his investigation at a former funeral home 17 years ago, where he witnessed an apparition of a demonic entity. The case was made into a Discovery Channel docudrama called A Haunting in Connecticut.

About 60% of the cases he investigates involve negative entities, Zaffis said, but that may be because of his association with clergy, who are called in to help with demonic hauntings or possessions. He is sometimes brought in during the "oppression" phase, a precursor to possession, where the afflicted person has begun to act extremely out of character. Most people who become possessed "open up doors" through the occult, allowing them to be invaded, he asserted.

He described a particularly intense case of a 52-year old woman who went through 16 exorcisms before she was freed. During an exorcism held at a church, the petite woman showed enormous strength and was able to break out of a straitjacket. In the last ritual, before the priest was able to drive out the entities, he said stereophonic voices emanated from her, her arms appeared scratched and burned, and the shape of a cross was seen etched into her stomach.