PITTSBURGH — A former librarian and a bookseller have pleaded guilty in the theft of rare books from the Carnegie Library of Pittsburgh in a years-long scheme.

Sixty-three-year-old Gregory Priore, former manager of the rare books room, pleaded guilty Monday to theft and receiving stolen property.

Fifty-six-year-old John Schulman, the owner of Caliban Book Shop, pleaded guilty to theft by deception, receiving stolen property and forgery.

Allegheny County prosecutors said some charges were withdrawn in exchange for the pleas, but the deal contains no agreement on sentencing, which is scheduled for April 17 for both defendants.

Authorities alleged earlier that Priore stole prints, maps and rare books and handed them off to Schulman to resell them.

Prosecutors said several hundred rare items worth more than $8 million were taken in a scheme investigators believed dated back to the 1990s.

Authorities said last year that one of the items stolen, a Geneva Bible published in 1615, was returned to the library after it was traced to the American Pilgrim Museum in Leiden in the Netherlands, about 45 miles from Amsterdam.

A newspaper in Pittsburgh reports that defense attorneys for Priore declined to comment following Monday’s hearing.

Schulman’s attorney, Albert Veverka, noted that his client wasn’t acknowledging any role in a conspiracy but said in a statement that he accepted responsibility “for his association with books under circumstances whereby he should have known that the books had probably been stolen.”