PITTSBURGH —Two men have been charged in what authorities are calling the world’s largest theft of library books.

More than $8 million in rare books were removed from the Carnegie Library of Pittsburgh, including Isaac Newton’s Principia Mathematica and a book signed by Thomas Jefferson.

A team of Pittsburgh city detectives moved in on the two suspects in a series of arrests on July 20 accusing the library’s popular archivist and local bookstore owner of a combined 30 theft charges that date back 20 years, a theft that has shaken the exclusive antiquarian book world.

Gregory M. Priore, 61, of Pittsburgh’s downtown Oakland neighborhood who worked alone as the sole archivist and manager of the library’s 30,000 rare book collection is charged with 20 counts of theft, conspiracy, forgery, receiving stolen property and criminal mischief.

John Schulman, 54, of Squirrel Hill, a nationally respected antiquarian bookseller and owner of the Caliban Book Shop located around the corner from the library, is charged with 10 counts of theft, dealing in proceeds of illegal activity, forgery, receiving stolen property, conspiracy, theft by deception and deceptive business practices.

If convicted, each man could face more than 10 years in prison and be fined tens of thousands of dollars and ordered to pay more than a million dollars in restitution.

Both men have been released on their own recognizance.

According to the Allegheny County District Attorney’s office, the two are accused of trafficking hundreds of rare books, maps and other items valued at just over $8 million by appraisers Pall Mall Art Advisors (PMAA). In some cases the books and items were sold to unsuspecting buyers on eBay, according to investigators.

In court documents, prosecutors described a conspiracy that began in 1997 where Priore schemed with Schulman to find the most valuable books within the library’s rare book section called the Oliver Room, named after former trustee William Oliver, at the library’s main branch in the heart of downtown Pittsburgh. Schulman’s bookstore specialized in poetry, literature, philosophy, art and Pennsylvania history.

Schulman has been a frequent guest on PBS’s Antique Roadshow appraising rare books as a member of the Antiquarian Booksellers Association of America (ABAA) where he also served on the Ethics and Standards Committee. Schulman resigned from the association on July 23.

Vic Zoschak, president of the ABAA said in a statement, “This is truly a regrettable situation for the larger book community, and one in which the Association shares the public’s dismay that such a theft took place. At this point...to comment further would be premature.”

Fellow member of the ABAA, Michael Vinson, a dealer based in New Mexico, said in an email to AntiqueWeek, “This is a huge deal. What makes this theft so unusual is the involvement of a major antiquarian book dealer – Schulman. These were great rarities and treasures. I’m just shocked at the depth of this thing.”

Schulman’s attorney Robert G. Del Greco, Jr., said in an email, “These are serious charges and we are treating them as such. Mr. Schulman is a titan in the rare book industry and is disappointed by these circumstances. We are reviewing the lengthy complaint and plan to address these allegations at the preliminary hearing. I am not in a position to offer further comment because of the pending legal matter.”

An attorney for Priore, Patrick Livingston, did not respond to inquiries for comment.

Suzanne Thinness, communication manager for the Carnegie Library, said in a statement, “We are grateful the investigation into the Oliver Room theft has resulted in arrests, however, we are deeply disappointed that at the center of this case are two people who had close, long-standing relationships with the Library. We have been asked not to comment further until legal proceedings are complete.”

In the 36-page lengthy complaint, investigators say Priore admitted his role in the thefts revealing how he often lifted the rare books or cut pages out of historic map books or other antiquarian volumes, slipped them into manila folders or simply rolled them up and carried them out the front door. He would drop them at Schulman’s bookshop on his way home from work.

Schulman would then sell the items online or to major book dealers. Through subpoenaed bank and other financial records investigators were able to trace the purchases to dozens of book collectors and dealers. Buyers returned their books after being contacted by the DA’s office.

Authorities also uncovered 37 stolen books listed on viaLibri.net, the world’s largest marketplace for old and rare books that had been posted by Schulman. When contacted by authorities, the listings were removed.

“Priore stated, ’I should have never done this. I loved that (Oliver) room, my whole working life, and greed came over me. I did it, but Schulman spurred me on,” the complaint reads. “Priore alleged that Schulman ’goaded’ him on and that Schulman made significantly more money that he did in the sale of the items from the Oliver Room.

“Priore explained that he took a lot of maps and pictures – in all possibly 200 items – from the Oliver Room. Priore then stated, ’You got me! I screwed up.”

Priore told investigators he stopped selling in late 2016 after he learned that the library was going to conduct an appraisal of the collection later the next year.

A team of appraisers from PMAA discovered 320 missing items and 16 that had been “cannibalized” with entire portions cut out of the book by an X-acto knife, according to the affidavit written by the district attorney’s detectives Frances Laquatra and Perann Tansmore.

“According to Pall Mall Art Advisors, the staggering scope of these library thefts – resulting in the loss of value of the CLP collection of approximately $8,066,300 – ranks it among the world’s largest (library) losses to date,” the detectives wrote.

After the discovery of the thefts last April, Priore was suspended and two months later was fired.

In a raid of the suspects’ homes and offices and after a nine-day search of the Caliban Book Shop Warehouse last summer, detectives discovered 42 “cannibalized” items valued at $258,945. To date, $1.1 million worth of stolen materials have been recovered by the combined efforts of the PMAA, the DA’s office and the art collecting community, the complaint said.

The most valuable book stolen, which has since been recovered, is Isaac Newton’s Philosophiae Naturalis Principia Mathematica, (Latin for Mathematical Principles of Natural Philosophy) first published in July 1687 and valued at $900,000.

The most valuable book still missing, according to the complaint, is a book of 1750’s etchings by Italian artist Giovanni Piranesi valued at $600,000.

An historic portfolio from the early 1900s of Native American Indians titled, The North American Indian by Edward S. Curtis,” was recorded with a “diminished value of $540,000” due to missing “photogravure images” cut out of the book. Investigators later found 231 Curtis images on eBay listed by the Caliban Book Shop with 171 images sold. Investigators say another 1,098 Curtis images are still missing.

The second most valuable missing work is The Journal of Major George Washington, by George Washington, valued at $250,000 according to a 13-page inventory of the recovered and missing items included with the complaint. The journal was written in 1754 when Washington was a 21-year-old major serving with the Virginia militia who just returned to Williamsburg from a 900-mile mission in the Ohio country.