This is an archived article that was published on sltrib.com in 2016, and information in the article may be outdated. It is provided only for personal research purposes and may not be reprinted.

Federal prosecutors in Baltimore on Thursday said they will charge a former National Security Agency contractor with violating the Espionage Act, alleging that he made off with "an astonishing quantity" of classified digital and other data in what is thought to be the largest theft of classified government material ever.

In a 12-page memo, U.S. Attorney Rod Rosenstein and two other prosecutors laid out a much more far-reaching case against Harold Martin III than was previously outlined. They said he took at least 50 terabytes of data and "six full banker's boxes worth of documents," with many lying open in his home office or kept on his car's back seat and in the trunk. Other material was stored in a shed on his property.

One terabyte is the equivalent of 500 hours worth of movies.

The prosecutors also said Martin had an "arsenal" of weapons in his home and car, including an assault-rifle-style tactical weapon and a pistol-grip shotgun with a flash suppressor.

Martin, who will appear at a detention hearing in U.S. District Court in Baltimore on Friday, also took personal information about government employees as well dozens of computers, thumb drives and other digital storage devices over two decades, the government alleged.

In a complaint unsealed earlier this month, the government charged him with felony theft of government property and the unauthorized removal and retention of classified materials, a misdemeanor. Conviction under the Espionage Act could send Martin to prison for up to 10 years on each count and is considered the most serious of the three charges.

Prosecutors will argue Friday that Martin, 51, of Glen Burnie, Maryland, presents "a high risk of flight, a risk to the nation and to the physical safety of others," and that he should not be released from jail.

"The case against the defendant thus far is overwhelming, and the investigation is ongoing," Rosenstein said. "The defendant knows, and, if no longer detained, may have access to, a substantial amount of highly classified information, which he has flagrantly mishandled and could easily disseminate to others."

Continued detention without bail is necessary, prosecutors said, because of "the grave and severe danger that pretrial release of the defendant would pose to the national security of the United States."

Martin's attorneys are expected to file their own memo before Friday's hearing.

The government also alleged that he took a top-secret document detailing "specific operational plans against a known enemy of the United States." Prosecutors did not name the enemy. The document, prosecutors said, contained a warning, in capital letters, that said: "This conop [concept of operations] contains information concerning extremely sensitive U.S. planning and operations that will be discussed and disseminated only on an absolute need to know basis. Extreme opsec [operational security] precautions must be taken."

Martin was not involved in the operation, the government said, and had no need to have the document or know its specifics.

Another document found in his car contained handwritten notes describing NSA's classified computer systems and detailed descriptions of classified technical operations, the prosecutors said. The notes also included descriptions of basic concepts associated with classified operations, as though intended for a general public audience, they said.

In an interview before his arrest, Martin initially lied to investigators, prosecutors said, denying having taken classified material. Only when confronted with specific documents did he admit that he took what he knew to be classified files and that "such actions were unauthorized and wrong," they said.

Martin had access to classified data beginning in 1996, when he was with the U.S. Navy Reserve, and that access continued through his employment with seven private government contractors.

The government alleged that Martin, "as a trusted insider," was able to defeat "myriad, expensive controls placed" on classified information. He was trained how to properly handle and store such data, but violated his oath and duty to do so, prosecutors said.

They said the devices seized show he made extensive use of sophisticated encryption and anonymization technologies. He also used a sophisticated software tool that runs without being installed on a computer and provides anonymous Internet access, "leaving no digital footprint on the machine," they said.

In August, a cache of highly sensitive NSA hacking tools mysteriously appeared online. Although investigators have not found conclusive evidence that he was responsible for that, he is the prime suspect, said U.S. officials, who spoke on the condition of anonymity because the investigation is ongoing.

That is the event that set off the search that turned up Martin, the officials said.

In July, according to the prosecutors' memo, he watched a video about how law enforcement authorities catch computer users who wish to remain anonymous on the Internet. "He has a demonstrated ability to conceal his online communications and his access to the Internet," the prosecutors said.

To support their argument that Martin poses a danger to the community, they noted that in late July, he went to Connecticut to buy a "Detective Special" police-package Chevrolet Caprice. While searching his house, the FBI also recovered 10 firearms, only two of which were registered, the government said.

Prosecutors said a loaded handgun was found in a case on the floorboard of the Caprice, in violation of Maryland law.

Martin's wife, Deborah Vinson, was "very upset" to learn about her husband's arsenal, prosecutors said, "as she had only been aware" of him having "one or two" firearms.

If Martin had taken the classified material "for his own edification, as he has claimed, there would be no reason to keep some of it in his car, and arm himself as though he were trafficking in dangerous contraband" prosecutors said.