The former soldier, Roderick James Ramsay, was accused of violating espionage laws against gathering or delivering defense information for a foreign government, the agency said.
A man violates the espionage laws because he doesn't hke spending a little extra time in the service of his country.
It is a violation of espionage laws simply to obtain classified information, even if no attempt is made to pass it to a foreign government.
Among the statutes being reviewed by the investigators are espionage laws that prohibit the disclosure, dissemination or publication of national security information.
However espionage laws are also used to prosecute non-spies.
Officials said they could not prove that the briefcase contained the sort of material covered by the espionage laws.
Still, his opponents remain skeptical, and in the symbology of modern Japan seemingly unrelated matters such as the espionage law get tossed into the overall debate.
The talks could resume at any time, but the failure to reach an early plea agreement was somewhat surprising to lawyers in the small circle of espionage law.
It modified a large body of law, including espionage law.
Existing espionage laws would provide an adequate basis for the prosecution of individuals who attempt to peddle governmental secrets to foreign governments.