One by one, rare books vanished from the library — the Journal of George Washington; a copy of Isaac Newton’s “Philosophiae Naturalis Principia Mathematica” valued at nearly $1 million; an Atlas by a 19th-century German explorer worth $1.2 million.

Over a quarter of a century, these printed treasures and hundreds of others were stolen from Pittsburgh’s Carnegie Library. And some of them were heading just around the corner.

On Monday, Gregory Priore, the former archivist of the Carnegie Library’s rare book room, and John Schulman, owner of Caliban Book Shop, pleaded guilty to theft and receiving stolen property for snatching $8 million worth of rare books, maps, folios, and other objects. Schulman also pleaded guilty to forgery. Their sentencing is scheduled for April.
 

Prosecutors say the scheme ran from 1992 to 2017, during which time Priore would steal the rare texts from the library’s R. Oliver Special Collections Room — sometimes simply walking right out of the building with them, prosecutors said — and pass them along to Schulman, who would sell them at his store and online.