Lurking in Robert E. Jackson's collection of more than eleven thousand American snapshots are some of the most peculiar photographs of ordinary people posing for the camera in their Halloween "best." Culled from anonymous family photographs found in auctions and other carefully selected archives, Jackson's eye for the curious and absurd remains unrivaled.  "I am interested in the dark side of snapshots, " says Jackson, " and what they tell us about our deepest fears and motivations.  There is a voyeuristic side to collecting which searching for Halloween photos brings out. It is the hidden which attracts."

So behold 13 of Jackson's unsettling Halloween gems. See more on his Instagram feed, or learn more about his practice in an interview we conducted earlier this year.