Bradley Manning. Reuters

Private First Class Bradley Manning pleaded guilty on Thursday to misusing classified material and nine other charges related to allegations that he illegally acquired and transferred classified U.S. government information to the anti-secrecy website WikiLeaks. However, Manning pleaded not guilty to the most serious charge, aiding the enemy, when he entered his guilty pleas in a hearing before his court martial, which is scheduled to begin on June 3.

The 25 year-old soldier pleaded not guilty to 11 of the most serious charges against him, including aiding the enemy. His case will go forward at a general court martial in June. If he is convicted of all the charges against him he could be sentenced to life in prison. Manning faces a maximum of up to 20 years in prison for the charges to which he pleaded guilty.

Manning reportedly admitted that he leaked a video of an Army helicopter intentionally shooting civilians and journalists in Iraq, which has become a widely viewed clip known as “Collateral Murder.” He also acknowledged that he released classified State Department cables, an Army field manual, and Army documents on Iraq and Afghanistan that detailed military operations in those countries.

According to online reports from individuals in the courtroom, Manning said he attempted to give the documents to both the Washington Times and the New York Times, which both rejected his offer, before he finally made it available to WikiLeaks. He also reportedly offered to give the video to Reuters, which had previously attempted to obtain the content.

According to tweets from Nathan Fuller, the editor of the Bradley Manning Support Network, Manning said on the stand that he was troubled because the soldiers in the video “seemed to not value human life by referring to [those shot] as ‘dead bastards.’”

He also said he believed the military became obsessed with “capturing and killing” when conducting counterterrorism operations.

WikiLeaks and its founder, Julian Assange, publicized the material worldwide. Manning was arrested in May 2010 while working as an intelligence analyst at a U.S. army base outside of Baghdad.

The young soldier spent more than two years in prison, including nine months in solitary confinement, before finally receiving a trial. On Tuesday a military judge refused a defense motion to dismiss the charges against Manning due to a lack of a speedy trial, ruling that the delays by the prosecution were excludable and justifiable.