His kindly small-town mailman look aside, what may have caught Reznor's attention was Silverthorne's famous series documenting the flow of ex-humanity through a morgue. Stemming from a conversation he had with his once-teacher Diane Arbus, Silverthorne's photos are stark, creepy, and touching. The odd formality gives the images a rigidly mannered look, but the matter-of-fact titles and crisp resolution of detail gives them a loose documentary feel (note the shots in which one can make out the leg and foot of the photographer in the pic).
Here's some pics from the morgue series:
Young Boy Hit By Car
Woman Who Died in Her Sleep, 1972
Couple Killed by Carbon Monoxide Poisioning
All thanks to that postmodern wonder cabinet, Quigley's Cabinet, for reminding me about Mr. Silverthorne's work.