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. He was brought into court in an orange jumpsuit and showed no visible reaction as he was sentenced by US District Judge Indira Talwani.

Earlier in the hearing he apologized before the judge.

Prosecutors had originally requested a 17-year sentence for Teixeira, saying he “perpetrated one of the most significant and consequential violations of the Espionage Act in American history.”

Defense attorneys had sought an 11-year sentence. In their sentence memorandum, they acknowledged that their client “made a terrible decision which he repeated over 14 months,” But they argued that Teixeira’s actions, though criminal, were never meant to “harm the United States.” He also had no prior criminal record.

The security breach raised alarm over the United States’ ability to protect its most closely guarded secrets and forced the Biden administration to scramble to try to contain the diplomatic and military fallout.