Petty Officer First Class Kristian Saucier, a 29-year-old mechanic, admitted he used his personal cellphone on three occasions in 2009 to take six pictures of the submarine's classified propulsion system while working in the engine room, according to court documents.

In a court filing, Saucier's lawyer compares the half-dozen classified photos Saucier had in his possession to the 110 classified emails the FBI determined were on Hillary Clinton's personal server.

"Mr. Saucier possessed six (6) photographs classified as 'confidential/restricted,' far less than Clinton's 110 emails," Derrick Hogan wrote to the US District Court in Bridgeport, Connecticut, in a story first reported by Politico.

Advocating for probation, Hogan said it would be "unjust and unfair" for Saucier -- who has pleaded guilty -- to do prison time "for a crime those more powerful than him will likely avoid."