Boston — Former Massachusetts Air National Guardsman Jack Teixeira, who admitted he illegally posted sensitive military information to online chat rooms in what prosecutors called one of the "most prolific" and "rare" government leak operations, was sentenced to 15 years in prison by a Boston federal judge on Tuesday.

Jack Teixeira, the Massachusetts Air National Guardsman who prosecutors said "perpetrated one of the most significant and consequential violations of the Espionage Act in American history," is set to be sentenced Tuesday in Boston federal court.

A Massachusetts Air National Guard member who pleaded guilty to leaking highly classified military documents about the war in Ukraine is expected to be sentenced in federal court Tuesday.