Historically, demonic possessions have been used to diagnose mental or physical illnesses and even strings of bad luck. But though the scientific community has debunked these outdated convictions, the ancient rite of casting evil spirits from the possessed is alive and well across the United States, with America being home to 20 percent of the world's exorcists.In the first part of our new series on this religious and paranormal practice, we speak with Father Vince Lampert, who is a member of the International Association of Exorcists, and Michael Shermer, founder of Skeptic magazine, to see why modern exorcism still exists in the West.Get the VICE App on iOS and Android