The retired Navy officer arrested for allegedly removing highly classified information from the National Security Agency worked with the organization's elite computer hackers, who specialize in using computer code to penetrate the systems of foreign nations, according to a former colleague and the man’s online resume.

Harold Thomas Martin, III, who goes by Hal, was also enrolled in a PhD program at the University of Maryland Baltimore County. The university has a partnership with the NSA, in which the agency helps develop curriculum for the school and agency employees can take classes there.

Martin worked with NSA’s Tailored Access Operations unit, sources with knowledge of his background told The Daily Beast. In his LinkedIn resume, Martin says he worked as a “cyber engineering advisor” supporting “various cyber related initiatives” in the Defense Department and intelligence community.

Allen was employed by NSA contractor Booz Allen Hamilton. “When Booz Allen learned of the arrest of one of its employees by the FBI, we immediately reached out to the authorities to offer our total cooperation in their investigation, and we fired the employee," Craig Veith, a vice president with the company, said in a statement. “We continue to cooperate fully with the government on its investigation into this serious matter.”

Martin was charged with two counts of mishandling classified information and theft of government property. According to the New York Times, which first reported his arrest, the FBI is investigating whether Martin stole classified computer codes that the NSA uses to break into foreign networks. The FBI discovered the material at Martin’s home in Maryland.

Martin’s case immediately drew comparisons to that of Edward Snowden, who was also working as a contractor for Booz Allen Hamilton when he stole classified documents that he gave to journalists. The NSA put in place so-called insider-threat detection programs after Snowden’s leaks to catch future unauthorized disclosures. But it wasn’t immediately clear whether those systems failed to spot Martin or if he removed the classified material before they were put in place.

Martin’s lawyer told the Wall Street Journal “There is no evidence that Hal Martin intended to betray his country.” He has also not been charged yet with espionage or attempting to provide the classified information to a third party or a foreign government.

Former intelligence officials, who said they aren’t familiar with Martin’s case, suggested he may have brought the material home to use as research for his PhD studies. “It’s conceivable given what he was working on that he might have used the [classified] material for research,” a former official said, speaking on condition of anonymity.

The university’s director of communications, Dinah Winnick, confirmed to The Daily Beast that Martin, 51, is a PhD student in the Information Systems program but said the school had no further comment.

It’s not known whether Martin’s PhD work related to his work at NSA, which focused on offensive cyber operations. But his description at the school’s Interactive Systems Research Center said Martin was looking at “new methods for remote analysis of heterogeneous & cloud computing architectures.” He presented a paper on the topic with his dissertation committee chair at a conference in Seattle in 2014.

His dissertation, currently in its fourth draft, according to a file on his personal homepage, is not publicly available. Members of Martin’s dissertation committee did not return The Daily Beast’s requests for comment.

According to Navy records, Martin served for twelve years -- four of them in the active component and the rest as a reservist. The highlight of his career appears to be his service on the USS Seattle, from April 1989 to July 1992. The Seattle, a fast combat support ship, was one of the first ships to arrive after Iraqi leader Saddam Hussein’s forces invaded Kuwait in 1990.

Wilbur Trafton, the commander of the Seattle during the war to liberate Kuwait, told The Daily Beast that he doesn’t remember the then-Lt. Martin. A second shipmate also said he couldn’t recall Martin.

Martin’s title at the time, Surface Warfare Officer, is a broad job description that reveals little about his work on the ship. The Seattle was decommissioned in March 2005.

Martin’s ex-wife, Marina, declined to discuss her former husband.