A former U.S. National Security Agency contractor has pleaded guilty to one charge of stealing a classified document as part of a plea deal first pitched in January.

Harold T. Martin III was arrested in August 2016 and was found in possession of 50 terabytes of government data, including documents marked “Secret” and “Top Secret.” Under the deal, Martin pleaded guilty to one count of willful retention of national defense information during a rearraignment hearing held in the Baltimore federal court Thursday, according to The Washington Times.

The one guilty plea, accepted by the prosecution, is a drop in the bucket compared with the 20 charges on which he was initially arrested. Martin was never alleged to have shared secret documents with third parties and instead simply hoarded them. His publicly appointed lawyers even went as far as claiming that Martin was hoarding documents to “improve his computer expertise.”

“They say somewhere along the line that turned into some kind of bizarre compulsion, some kind of hoarding,” NPR’s Carrie Johnson reported Thursday. “And Martin wound up taking home so much stuff, he couldn’t even absorb it all. A lot of it, the FBI found gathering dust in an unlocked shed in Martin’s backyard.”

He was, however, a prime suspect in leaks of NSA documents and spy tools that were obtained and published by The Shadow Brokers at one stage.

Prosecutors have asked that Martin be jailed for nine years. “The American people entrusted Harold Martin with some of the nation’s most sensitive classified secrets,” Assistant Attorney General John Demers said in a statement. “In turn, Martin owed them a duty to safeguard this information.”

Sai Chavali, security strategist at ObserveIT Ltd., previously told SiliconANGLE that although cybersecurity professionals are not normally considered potential insider threats, they have the technical prowess to protect the firm’s sensitive data on a daily basis.

“Given the right motivations and circumstances, professionals, like Mr. Martin, can cause greater harm by exfiltrating and leaking those same crown jewels,” Chavali said. “Martin’s approach takes advantage of outdated approaches to security to exfiltrate volumes of data, potentially more harmful than the Snowden incident in 2013.

The case is also notable in how it came to the NSA’s attention. Martin’s arrest came via employees from Russian cybersecurity firm Kaspersky Lab working in conjunction with the NSA.

Martin’s sentencing hearing is scheduled for July 17.

Photo: NSA/Wikimedia Commons