Who is the author,do you remember?
Thomas B. Allen
it was the recommended reading at the bottom of the story you posted. It was an analysis of the exorcisms in Georgetown and St. Louis of a boy who lived in Cottage City, MD in 1949. The exorcism diary and the recollections of one priest who was involved (not as an exorcist, but as someone who restrained the boy) formed the main part of the study