Investigators have little doubt that a National Security Agency contractor arrested in August hoarded mountains of classified material, but so far they've found no evidence that he leaked anything to anyone, The New York Times reported Friday.

"Let’s just say he’s only a psycho hoarder and he keeps this stuff with his old copies of National Geographic and his collection of lunchboxes," said an administration official, who also asked not to be named. "That’s still extremely troubling to anyone in national security, because people like that don’t keep track of where things are or with whom they are talking." In Mr. Martin’s case, the official said, the sloppy handling "is particularly worrisome—we are talking sources and methods, tactics, techniques and procedures. Those are the things we guard most closely."

Still, even if Harold T. Martin III didn't intentionally leak anything, federal officials remain highly concerned. Martin's home computers had "minimal security protection," leaving open the possibility, however remote, that hackers broke in and stole data that could compromise vital national security programs. As the NYT reported:

On seven occasions in the last three years, top-secret information has leaked from the NSA, raising concerns that leakers remain at large in a post-Edward Snowden agency. Martin's former wife portrayed her ex-husband, a former Navy officer, as a loyal US patriot who probably took the material so he could work on it at home. The hoarding occurred over years. At first, material was snuck out on paper, then on CDs, and eventually on thumb drives.

A former PhD mentor at the University of Maryland, Baltimore County, where Martin was a PhD candidate, also portrayed Martin as dedicated and thoughtful. But the mentor also said Martin seemed to believe his research into offensive computer security was under-appreciated on a campus where students and faculty had little understanding of the military.

Over the past few years, two leaks in particular have concerned officials. One involved techniques the NSA uses to penetrate targeted computers even when they're not connected to the Internet. Another published by WikiLeaks identified eavesdropping targets and included transcripts of intercepted communications from American allies. So far, investigators are skeptical that the information came from Martin, but they are continuing to look for connections.

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