More secret material was found in a shed in his yard and in his auto, officials said.
The amount of stolen data is estimated to be at least fifty terabytes, enough to fill dozens of hard drives, prosecutors said, adding that the alleged criminal conduct 'is breathtaking in its longevity and scale'.
A judge holds a hearing on Martin's detention request Friday afternoon. Investigators have yet to find definitive evidence Martin sold the information to Russia, but have evidence that Martin communicated with others online in Russian.
According to the Wall Street Journal, prosecutors said Martin had become heavily armed, stockpiling 10 weapons, and had taken precautions to cover his tracks. If convicted, Martin faces a maximum sentence of one year in prison for unauthorized removal of classified data, and 10 years in prison for theft of government property.
In addition, the filing suggested that Martin might have stored secret documents electronically in a hidden place in the "cloud" where he could gain access to them if released, using specialized software to try to hide his electronic tracks.
"The case against the defendant thus far is overwhelming, and the investigation is ongoing", said Rosenstein, assistant US attorney Zachary Myers and trial attorney David Aaron.
"It is readily apparent to every foreign counterintelligence professional and nongovernmental actor that the Defendant has access to highly classified information", the filing said.
His lawyers have submitted a memo arguing that he is not a flight risk and should be released under any conditions that the court wishes to impose, pending trial.
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Martin does not appear to have a valid passport and investigators have not said he sent information to foreign governments.
Martin's wife and home are in Maryland, they said.
The Justice Department said Martin apparently lacks a USA passport. Martin's public defenders, James Wyda and Deborah Boardman, have said that he presents no flight risk and that "there's no evidence he meant to betray his country". According to an affidavit, Martin was a contractor with the federal government and had a top secret national security clearance.
"Among the many other classified documents found in the Defendant's possession was a document marked as "Top Secret/Sensitive Compartmented Information" ('TS/SCI') regarding specific operational plans against a known enemy of the United States and its allies", the court document said.
The documents became Martin's "treasures", Wyda said.
So far, court documents don't specify what Martin is accused of doing with the information that he took, which is used to hack the computer networks of foreign governments. "The handwritten notes also include descriptions of the most basic concepts associated with classified operations, as if the notes were intended for an audience outside of the Intelligence Community unfamiliar with the details of its operations", prosecutors said in their filing.
In an interview before his arrest, Martin denied having taken classified material, and only admitted to it when confronted with specific documents, prosecutors said. But there is no indication that Martin gave the information to anyone else.