From the Atlas Obscura:
On the evening of December 7, 1981, Dianne Melnychuk, serials librarian at the Haas Library at Muhlenberg College in Allentown, Pennsylvania, noticed an unfamiliar gray-haired man of early middle age lingering around the card catalog near her desk. He had attempted to appear inconspicuous by way of nondescript, almost slovenly dress, but at almost six-and-a-half feet tall, with a 225-pound frame, he stood out.
Something about him rang a bell. Melnychuk discreetly followed him up to the sixth level of the stacks, and carefully observed him from the end of a row of shelving. In spite of the glasses he wore that evening, his face clicked in her memory.
A few months earlier, a photo of this man, who went by the name James Richard Shinn, had appeared in an article published in Library Journal. Patricia Sacks, director of the Muhlenberg and Cedar Crest College Libraries, had shared the article with her staff with an accompanying memo: “Take a good look at the face,” she wrote, “and, more importantly, keep your eye on strangers whose behavior may be a tipoff.”
James Richard Shinn was a master book thief. Using expert techniques and fraudulent documents, he would ultimately pillage world-class libraries to the tune of half a million dollars or more. A Philadelphia detective once called him “the most fascinating, best, smartest crook I ever encountered.” And yet, despite the audacity of his approach and the widespread effects of his crimes, Shinn has been relegated to a footnote in book history.
. . . .
Shinn’s motel room contained 26 stolen books and a file full of inventory cards for another 154 volumes. He was well-educated in book history, restoration and binding, and the tools of his trade filled the room: color-stained cloths and Q-tips with jars of shoe polish, used to color-match and conceal library markings on book spines. A folder of facsimile title pages, used as replacements when a book’s true title page was stamped or contained other identifying marks. All were designed to remove libraries’ marks and render the stolen works unidentifiable and thus saleable to unsuspecting book dealers and collectors.
Link to the rest at Atlas Obscura