You might find this interesting.
https://www.newscenter1.tv/fbi-arrests-lead-man-for-attempted-espionage/
This case from last year was mentioned by a DUer, and although not completely on point, it does illustrate what a complaint for espionage might look like. You can access the complaint by following the links (one at the top, and a further link at the bottom. The link at the bottom is a pdf.)
18 USC Code Section 641 has to do with public money, property, or records:
"Whoever embezzles, steals, purloins, or knowingly converts to his use or the use of another, or without authority, sells, conveys or disposes of any record, voucher, money, or thing of value of the United States or of any department or agency thereof, or any property made or being made under contract for the United States or any department or agency thereof; or
Whoever receives, conceals, or retains the same with intent to convert it to his use or gain, knowing it to have been embezzled, stolen, purloined or converted..." and it goes on to say the penalty could be up to ten years with a fine.
One interesting point is that the arrest warrant can be executed by "any authorized law enforcement officer." It doesn't have to be anyone from the FBI, just someone with arrest powers.
An affidavit in support of the search warrant is what the Repubs are now trying to obtain. This particular search warrant details quite a bit regarding this man's attempt to transmit classified docs to Russia; but 641 doesn't require the sale, just the part about gathering up the records, like you could do when vacating the WH and placing highly classified docs in a basement.
When is the J6 Committee due to return? And, Bannon is going to get sentenced in October. And then, November...