David Slater, 64, who had top secret clearance at his job at the U.S. Strategic Command at Offutt Air Force Base in Nebraska, pleaded guilty to a single count before a federal magistrate judge in Omaha on Thursday. In exchange for his guilty plea, two other counts were dropped.

Slater remains free pending his sentencing, which is scheduled for Oct. 8. Prosecutors and his lawyers agreed that he should serve between five years and 10 months and seven years and three months in prison, and the government will recommend a term at the low end of that range. The charge carries a statutory maximum of 10 years behind bars.

U.S. District Judge Brian Buescher will ultimately decide whether to accept the plea agreement and will determine Slater’s sentence.

“I conspired to willfully communicate national defense information to an unauthorized person,” Slater said in a handwritten note on his petition to change his plea.

Slater had access to some of the country’s most closely held secrets, John Eisenberg, assistant attorney general for national security, said in a statement.

“Access to classified information comes with great responsibility,” said Lesley Woods, the U.S. attorney for Nebraska, said in the same statement. “David Slater failed in his duty to protect this information by willingly sharing National Defense Information with an unknown online personality despite having years of military experience that should have caused him to be suspicious of that person’s motives.”

Slater retired from the Army as a lieutenant colonel in 2020 and worked in a classified space at the base from around August 2021 until around April 2022. He attended briefings about the Russia-Ukraine war that were classified up to top secret, court documents say. He was arrested in March of 2024.

In his plea agreement, he acknowledged that he conspired to transmit classified information that he learned from those briefings via the foreign dating website’s messaging platform to an unnamed coconspirator, who claimed to be a woman living in Ukraine. The information, classified as secret, pertained to military targets and Russian military capabilities, according to the plea agreement.

“Defendant knew and had reason to believe that such information could be used to the injury of the United States or the advantage of a foreign nation,” the agreement states.

According to the original indictment, the coconspirator regularly asked Slater for classified information. She called him, “my secret informant love!” in one message. She closed another by saying, “You are my secret agent. With love.” In another, she wrote, “Dave, I hope tomorrow NATO will prepare a very pleasant ‘surprise’ for (Russian President Vladimir) Putin! Will you tell me?”

Court documents don’t identify the coconspirator, or say whether she was working for Ukraine or Russia. They also don’t identify the dating platform.

Amy Donato, a spokesperson for the U.S. attorney’s office in Omaha, said Monday that she couldn’t provide that information. Slater’s attorney, Stuart Dornan, didn’t immediately return a call seeking further details.