Jonathan Toebbe, a Navy nuclear engineer, pleaded guilty Monday to one count of "Conspiracy to Communicate Restricted Data" after he snuck classified documents to federal agents posing as foreign spies.
Toebbe, 43, who admitted guilt as part of a plea deal, will now face about 12 to 17 years in prison, avoiding the possibility of a life sentence, according to court records.
He was arrested in October 2021 along with his wife, Diana, though many details of the couple's offenses were not made public at the time.
Read Next: Defense Secretary Austin Heads to Europe as Putin Readies Ukraine Invasion Force
According to new information in the plea document, both prosecutors and Toebbe's lawyers agree that the nuclear engineer made four "dead drops" between June and October 2021. His wife allegedly acted as a lookout in three of those instances.
A dead drop is a spycraft term that describes the practice of one person leaving materials in a pre-arranged location for another person to pick up later, thus avoiding direct contact between them.
On his first drop, Toebbe put "militarily sensitive design elements, operating parameters, and performance characteristics of Virginia-class submarine reactors on an SD card, which was wrapped in plastic and concealed between two slices of bread on a half of a peanut butter sandwich," according to the plea.
That SD card also contained a typed message that said: "I hope your experts are very happy with the sample provided" and "I want our relationship to be very successful for us both."
On his second drop, Toebbe left behind a typed message that laid out a plan for him to leak "51 packages over time in exchange for a total of $5 million paid in cryptocurrency."
"The message also included statements that the information 'was slowly and carefully collected over several years' and 'smuggled past security checkpoints a few pages at a time' and that one of the sets of information 'reflects decades of U.S. Navy 'lessons learned' that will help keep your sailors safe,'" according to the plea document.
The next two drops involved Toebbe hiding SD cards in packets of chewing gum.
Prosecutors have not revealed for whom Toebbe believed he was spying. The plea agreement references agents posing as representatives of "COUNTRY1."
Before making the four drops, Toebbe traveled to Washington, D.C., around the end of May 2021 to view a "physical signal … that had been placed at a location associated with COUNTRY1" as a way of assuring him of their legitimacy.
The documents also suggest that Toebbe was ready to abandon his life in the U.S. should he be discovered. "'We have cash and passports set aside for th[e] purpose' of having to flee the United States," he wrote in a message on his third drop.
Investigators paid the engineer more than $100,000 in cryptocurrency as part of the investigation, money that he has agreed to help officials recover. Toebbe has also agreed to allow agents to search much of his property and devices for more classified or restricted information.
Diana Toebbe's case is ongoing; she faces three charges of "Communication of restricted data -- sabotage."
According to an apparent LinkedIn page for Toebbe, he claimed to have worked as a nuclear engineer for the Navy's Nuclear Reactor department and was the technical lead for Columbia-class submarine nuclear design. Court records from early in his case described him as "a current employee of the United States Navy."
The plea agreement noted that Toebbe “had access to information concerning the Virginia-class submarine, including, but not limited to, information relating to militarily sensitive design elements, operating parameters, and performance characteristics of Virginia-class submarine reactors.”
-- Konstantin Toropin can be reached at konstantin.toropin@military.com. Follow him on Twitter @ktoropin.
Related: Navy Engineer and Wife May Face Life in Prison for Allegedly Trying to Sell Nuclear Sub Secrets