Since then, he admitted to sending troves of material to the anti-secrecy website WikiLeaks and pleaded guilty to charges that would send him to prison for up to 20 years. The U.S. military and the Obama administration weren’t satisfied, though, and pursued a charge of aiding the enemy, which carries a potential life sentence.

The trial on that most serious charge and 20 other offenses begins Monday for the 25-year-old former intelligence analyst from Oklahoma. It’s the most high-profile case for an administration that has come under criticism for its crackdown on leakers. The six prosecutions since Obama took office is more than in all other presidencies combined.

Manning chose to have his court-martial heard by a judge instead of a jury. It is expected to run all summer.