The following information is taken directly from the Masks of Nyarlathotep campaign book, one of the finest suppliments in a long line of great supliments Chaosium has released for Call of Cthulhu.  If you're interested in running the campaign, don't try to crib together what scraps you can here; get the book.  I do play with a lot of the information and you never know when I might have shifted something to make it more smooth for my players, added something in, or ignored a bit I didn't want to use.  Get the Masks of Nyarlathotep book; it's well worth it.  These clippings are provided as player hand outs as part of the campaign.  They are Chaosium's property and used with their permission which is in the book.
 

Jackson Elias is a writer and anthropologist who's written numerous stories for Exotic Oddities usually to promote a book he's written on the same subject.  His writings characterize and analyze death cults.  In fact, his rather pulp adventurish recountings of his encounters with them was partially the inspiration for the true occult section of the magazine.  His best known book is Sons of Death which exposing modern day Thuggees in India.  He speaks several languages fluently and is constantly travelling.  He is social and enjoys an occasional drink as well as smokes a pipe.  Elias is tough, stable, and punctual, unafraid of brawls or officials.  He is mostly self-educated.  His well researched works always seem to reflect first-hand experiance.  He is secretive and never discusses what he is working on until he has a first draft in hand. Elias is 38, of medium height and build, and dark-complexioned.  He has a fiesty, friendly air about him and, as an orphin in Stratford, Connecticut, he learned to make his own way early in life.  He has no living relatives and no permanant address. All of his books illustrate how cults manipulate the fears of their followers.  A skeptic, Elias has never found proof of supernatural powers, magic, or dark gods.  Insanity and feelings of inadequacy characterize death cultists, feelings for which they compensate by slaughtering innocents to make them feel more powerful or chosen.  Cults draw the weak minded, though cult leaders are usually clever and manipulative.  When fear of a cult stops, it vanishes. Elias's books include: Skulls Along the River (1910)- exposes headhunter cult in the Amazon basin Masters of the Black Arts (1912) - Surveys supposed sorrcerous cults throughout history The Way of Terror (1913) - analyzes systemization of fear by cult organizations; warmly reviews by George Sorel The Smoking Heart (1915) - fist half discusses historic Mayan death cults; second half instances in present day Central America Sons of Death (1918) - modern day Thuggees; Elias infiltrated the cult and wrote a book about it Witch Cults of England (1920) - summerizes covens in nine English counties; interviews several practicing English witches;  Rebecca West thought some of the material was trivial and overworked The Black Power (1921) - Expands on The Way of Terror and includes several interviews with anonymous cult leaders All of the books are published by Prospero Press, a small publisher specializing in occult subjects.  They have a good working relationship with Exotic Oddities and several cross promotions between their authors and the magazine have taken place.  All of their works are edited by Jonah Kensington who you've gotten to know through this.