A federal judge Tuesday rejected plea bargains for a Navy engineer and his wife who allegedly tried to sell military secrets, saying the prison terms called for by the deals were too lenient for a couple accused of offering U.S. nuclear submarine data to a foreign government.

Jonathan Toebbe, 43, a civilian engineer for the Navy, and Diana Toebbe, 46, a private-school teacher, lived in Annapolis, Md., before they were arrested in October in a case involving a year-long FBI sting and cloak-and-dagger elements that seemed straight out of a spy novel, including the attempted transfer of confidential submarine data hidden in a peanut butter sandwich, authorities said.

In plea bargains with federal prosecutors - signed early this year and initially accepted by a federal magistrate - the couple admitted to violating the Atomic Energy Act. The deals called for Jonathan Toebbe to be sentenced to 12 1/2 to 17 1/2 years in prison, while his wife would get a three-year term. But the couple withdrew their guilty pleas Tuesday after U.S. District Judge Gina M. Groh, in Martinsburg, W.Va., threw out the agreements rather than impose the required sentences.

"It's not in the best interest of this community or, in fact, this country to accept these plea agreements," she said from the bench. "I don't find any justifiable reason for accepting either one of these plea agreements."

For nearly an hour before Groh's surprise ruling, two defense lawyers and an assistant U.S. attorney had argued, to no avail, that the prison terms called for in the deals were appropriate.

The 12 1/2-to-17 1/2-year range for Jonathan Toebbe is "not a slap on the wrist," his lawyer, Nicholas J. Compton, told the judge. "It's significant punishment." Diana Toebbe's attorney, Barry P. Beck, said a shorter term was right for his client because "she's not why we're here today. We're here because her husband had an ill-conceived idea to make money, and she agreed to go along with it."

Although she has raised doubts about plea deals in the past, Groh said, "In the end, I generally honor plea agreements negotiated by the parties, even when they have binding [sentencing] ranges" that she does not entirely agree with. In this case, however, "I find the sentencing options available to me to be strikingly deficient," the judge said.

U.S. Attorney William Ihlenfeld of the Northern District of West Virginia, where the case is being handled, said his office "will move forward" and "be ready" for a trial. "I respect the decision by the Court to reject the plea agreements," he said in a statement.

Defense attorneys, who appeared in Groh's courtroom for sentencing hearings Tuesday and seemed taken aback by her decision, did not immediately respond to messages seeking comment.

Jonathan and Diana Toebbe had each pleaded guilty to one count of conspiring to share "restricted data" in violation of the Atomic Energy Act, which carries a possible life sentence. After they withdrew their pleas, the judge set a joint trial date for mid-January. It is possible that before then, the two sides will negotiate new plea deals with sentences more palatable to Groh.

Jonathan Toebbe, a nuclear engineer with top-secret security clearance, worked in the Navy's multibillion-dollar effort to build submarines that can stay submerged and undetected for the longest time possible. His wife, a teacher at the private Key School in Annapolis, was known as a meticulous humanities instructor who had liberal political views and was loved by students. Both come from families with considerable military ties.

Authorities said the Toebbes, who have two children, schemed together to offer to sell government secrets about nuclear propulsion systems on U.S. submarines to an unidentified foreign country. According to court papers, investigators learned of the plot after the country forwarded the couple's sales pitch to U.S. counterintelligence officials.

FBI agents posing as representatives of the foreign country quickly launched a sting operation. Agents said they recorded Toebbe and his wife leaving data cards for their supposed handlers at "dead drop" sites within driving distance of their home. The information was hidden inside a peanut butter sandwich, an adhesive-bandage wrapper and a package of Dentyne gum, authorities said.

In fact, Jonathan Toebbe's foreign handler was an undercover FBI agent. Emails cited in court papers show that Toebbe came to trust the undercover agent in part because of the money he was paid and because the FBI arranged to "signal" Toebbe from the foreign country's embassy in Washington over Memorial Day weekend last year. The papers do not describe how the FBI was able to arrange such a signal.

In correspondence with his handler, Jonathan Toebbe claimed to have spent years formulating his "spy for hire" plan. In total, officials said, Toebbe provided thousands of pages of documents, and his espionage ambitions had been building for years.

Referring to the proposed sentence for Jonathan Toebbe, Groh wondered aloud what might happen if "he gets out early for good [behavior], and the information he still possesses and has access to is still in step with current technology - and he uses that and provides it to another country that gains an advantage over this country." She said the same about Diana Toebbe.

In a victim impact statement filed with the court, Vice Adm. William Houston, commander of U.S. submarine forces, said that the secrets the couple allegedly tried to sell were "some of the most secure and sensitive information about our nuclear powered fleet."

Reading parts of the statement from the bench, Groh said the data represents a "military advantage afforded by decades of research and development. This information could provide foreign navies with the opportunity to close the gap in capabilities which would require extraordinary effort and resources to restore."

At a court hearing shortly after the couple's October arrest, an FBI agent testified that authorities had searched the Toebbe home and their computers but had found neither the $100,000 in cryptocurrency that the U.S. government paid the couple, nor thousands of additional pages of secret documents the FBI says Toebbe stole from his job.

It is unclear whether the cryptocurrency or documents have since been recovered. The couple's now-cancelled plea agreements had called for them to cooperate with the FBI in its continuing investigation.