BOSTON — A federal judge on Tuesday sentenced a Massachusetts Air National Guard member to 15 years in prison after he pleaded guilty to leaking highly classified military documents about the war in Ukraine.

Jack Teixeira pleaded guilty earlier this year to six counts of willful retention and transmission of national defense information under the Espionage Act following his arrest in the most consequential national security case in years. Teixeira, who was brought into court wearing an orange jumpsuit, showed no visible reaction as he was sentenced by U.S. District Judge Indira Talwani.

Before being sentenced, Teixeira apologized for his actions.

“I wanted to say I’m sorry for all the harm that I brought and caused,” Teixeira said, referencing the “maelstrom” he caused to friends, family anyone affected overseas. “I understand all the responsibility and consequences fall upon my shoulders alone and accept whatever that will bring,” he added, standing as he addressed the judge.

Afterward, Teixeira hugged one of his attorneys and looked toward his family and smiled before he was led out of the court.

The security breach raised alarm over America’s ability to protect its most closely guarded secrets and forced the Biden administration to scramble to try to contain the diplomatic and military fallout. The leaks embarrassed the Pentagon, which tightened controls to safeguard classified information and disciplined members found to have intentionally failed to take required action about Teixeira’s suspicious behavior.

Earlier in Tuesday’s hearing, Assistant U.S. Attorney Jared Dolan argued that 200 months – or a little more than 16 ½ years – was appropriate given the “historic” damage caused by Teixeira’s conduct that aided adversaries of the United States and hurt the country’s allies. He also said that recommendation by prosecutors would send a message to anyone in the military who might consider similar conduct.

“It will be a cautionary tale for the men and women in the U.S. military,” Dolan said. “They are going to be told, ‘This is what happens if you break your promise, if you betray your country.’ … They will know the defendant’s name. They will know the sentence the court imposes.”

But Teixeira attorney Michael Bachrach told the judge in court Tuesday that 11 years was sufficient.

“It is a significant, harsh and difficult sentence, one that will not be easy to serve,” Bachrach said. “It will serve as an extreme deterrent to anyone particularly young servicemen. That is enough to keep them deterred from committing serious conduct.”

Teixeira, of North Dighton, Massachusetts, had pleaded guilty in March to six counts of the willful retention and transmission of national defense information under the Espionage Act. That came nearly a year after he was arrested in the most consequential national security leak in years.

The 22-year-old admitted that he illegally collected some of the nation’s most sensitive secrets and shared them with other users on the social media platform Discord.

When Teixeira pleaded guilty, prosecutors had said they would seek a prison term at the high end of the sentencing range. But defense attorneys wrote in their sentencing memorandum earlier that the 11 years is a “serious and adequate to account for deterrence considerations and would be essentially equal to half the life that Jack has lived thus far.”

His attorneys described Teixeira as an autistic, isolated individual who spent most of his time online, especially with his Discord community. They said his actions, though criminal, were never meant to “harm the United States.” He also had no prior criminal record.

“Instead, his intent was to educate his friends about world events to make certain they were not misled by misinformation,” the attorneys wrote. “To Jack, the Ukraine war was his generation’s World War II or Iraq, and he needed someone to share the experience with.”

Prosecutors, though, countered that Teixeira does not suffer from an intellectual disability that prevents him from knowing right from wrong. They argued that Teixeira’s post-arrest diagnosis as having “mild, high-functioning” autism “is of questionable relevance in these proceedings.”

Teixeira, who was part of the 102nd Intelligence Wing at Otis Air National Guard Base in Massachusetts, worked as a cyber transport systems specialist, which is essentially an information technology specialist responsible for military communications networks. He remains in the Air National Guard in an unpaid status, an Air Force official said.

Authorities said he first typed out classified documents he accessed and then began sharing photographs of files that bore SECRET and TOP SECRET markings. Prosecutors also said he tried to cover his tracks before his arrest, and authorities found a smashed tablet, laptop and an Xbox gaming console in a dumpster at his house.

The leak exposed to the world unvarnished secret assessments of Russia’s war in Ukraine, including information about troop movements in Ukraine and the provision of supplies and equipment to Ukrainian troops. Teixeira also admitted posting information about a U.S. adversary’s plans to harm U.S. forces serving overseas.