(CNN) -- A federal judge on Wednesday sentenced a self-proclaimed presidential historian who once claimed to have moved among White House circles to seven years in prison for conspiracy and theft of historical documents worth more than a million dollars.
U.S. District Judge Catherine C. Blake in Baltimore ordered Barry H. Landau's prison sentence to be followed by three years of supervised release.
Landau, 63, admitted in a plea agreement to having stolen from museums in Maryland, Pennsylvania, New York and Connecticut and having sold some of those documents for profit.
Blake also ordered Landau to pay a total of $46,525 to three dealers who bought documents from him without knowing they were stolen and to forfeit the more than 10,000 documents found in his New York apartment. More than 6,000 of them were stolen, prosecutors said.
"The evidence proved that Barry H. Landau was a con artist who masqueraded as a presidential historian to gain people's trust so he could steal their property," said U.S. Attorney Rod J. Rosenstein in a news release. "The revelation that Mr. Landau was a prolific thief sent a wake-up call to museums, libraries and other institutions that entrust valuable historical items to persons who claim to be engaged in academic research."
A number of historical documents were returned to the museums that had been victimized, said FBI Special Agent in Charge Richard A. McFeely. "What these documents stood for caused local and federal agencies to unite together to ensure that key pieces of our country's history will remain forever accessible for our citizens."
According to Landau's plea agreement, he and his co-conspirator, Jason Savedoff, 24, stole documents from historical societies, the University of Vermont and the Franklin D. Roosevelt Presidential Library from December 2010 through July 2011.
At the sentencing, prosecutors introduced evidence that Landau stole at least one item from the William McKinley Presidential Library and Museum in Ohio in 2005; 17 to 100 items from the Culinary Arts Museum in Rhode Island in 2008; and more than 250 items from Betty Currie, a former White House secretary, in 2010.
Evidence presented at the sentencing hearing and court documents show that Landau had been stealing presidential documents and memorabilia for years before he met Savedoff, and it was Landau who taught Savedoff how to steal, the news release said.
"Landau developed protocols to distract curators while items were pilfered, scheduled visits to repositories and requested access to collections containing marketable documents," it said. "It was Landau who dealt exclusively with purchasers of stolen items."
According to the plea, the two men sometimes concealed documents inside clothing that had been modified to contain hidden pockets. They often removed the libraries' card catalog entries for the items that they stole, thereby making it more difficult for the library staff to know that they were missing, it said.
Among the stolen materials were seven "reading copies" of speeches from the Franklin D. Roosevelt Presidential Library and Museum in Hyde Park, New York, on December 2, 2010, the plea agreement says.
"Reading copies" are the copies of the speeches from which Roosevelt read, and contain his edits and his signature.
Later that month, Landau sold four of them to a collector for $35,000, it says.
Three other "reading copies" of Roosevelt's inaugural addresses, valued at more than $100,000 apiece, were found in Landau's apartment. They included the water-stained reading copy of the inaugural address delivered by the new president in a rain in 1937.
On March 17, 2011, the two men took a 1780 letter from Benjamin Franklin to John Paul Jones from the New York Historical Society in New York City that prosecutors say is worth hundreds of thousands of dollars. Other documents stolen from the New York Historical Society include letters and documents authored by John Jay, Alexander Hamilton and President George Washington.
The two were caught on July 9, 2011, when they visited the Maryland Historical Society. Curators became suspicious and called the police, who found 79 documents inside a computer bag in a museum locker to which Savedoff had the key, the release says.
Sixty of the documents had been taken from the Maryland Historical Society, including a land grant dated June 1, 1861, and signed by President Abraham Lincoln; the others were from collections from other institutions.
Authorities say Landau talked of having dined at the White House and met past presidents, but they believe many of his stories might not be true.
Experts who have checked records found Landau, at best, exaggerated his supposed relationships with past presidents. He had appeared on several news outlets, including CNN, as a self-proclaimed presidential historian.
A Washington Post account in July quoted sources who questioned Landau's claims of relationships with the high and mighty in government circles over some 20 years.
Savedoff, also of New York City, has pleaded guilty to the same charges. No date has been set for his sentencing.