Retired professor and art expert Anthony Melnikas, the veteran researcher accused of cutting pages from a Vatican manuscript with a penknife and later attempting to sell them to a rare book dealer, now faces up to ten years in prison in the United States.
A Grand Jury indicted the former Ohio State University professor, aged 68, on four federal counts of receiving, possessing and smuggling three pages from a manuscript commissioned by Petrarch, the 14th-century scholar. He will remain free pending the trial, prosecutors said.
The art history world was profoundly shocked when possible evidence of a serious crime by a tenured professor and Vatican researcher of 30 years standing first emerged last year.
The professor has not been charged with theft because the alleged crime took place outside United States borders, sources said.
Neither Mr Melnikas nor his attorney were available for comment. US attorney Edmund Sargus in Columbus, Ohio, refused to discuss whether the two sides were negotiating a plea bargain.
Mr Sargus said the investigation had drawn in both Italian and Vatican authorities, as well as the US Customs, State, and Justice Departments.
"Customs agents frequently recover stolen art and antiquities, but seldom in Ohio," he said, and promised to return the pages to their rightful owner when the case was closed.
Mr Sargus said later that "there is still an ongoing investigation" into the case. It apparently involves a fourth page whose origin has yet to be traced, a leaf from a 14th century copy of the Justinian codes that Mr Melnikas also allegedly offered for sale. It was not found to be missing from the Vatican library.
Princeton University professor James Marrow first identifed and traced the three Petrarch leaves when they were brought to him by an Akron book dealer, and alerted customs. But the fourth leaf proved more mysterious.
The charges of receiving and possessing stolen property carry a maximum ten years and $250,000 fine, and the two counts of smuggling a maximum five-year term.
No trial date has been set. But if Professor Melnikas should be found guilty, the length of his sentence could rest on a difficult question: the amount of financial loss to the victim.
The Vatican gave him access to the Petrarch manuscript in 1987, but did not discover the pages were missing until it was alerted by Professor Marrow.
If the pages are found to be worth more than $10,000, he faces a minimum one-year jail term under federal sentencing guidelines. "A big factor in determining the appropriate sentence will be the value of the artwork," said Mr Sargus.