National Guard soldier of the Massachusetts Air National Guard Jack Teixeira has admitted his guilt in the leak of secret Pentagon documents that occurred last year, reports ABC News. According to the signed plea agreement, Teixeira will serve 16 years in prison. He agreed to plead guilty to all six counts of intentional retention and transmission of national defense information. In exchange, prosecutors agreed not to bring additional charges against him under the espionage statute. As part of the deal, the suspect is required to undergo debriefings with representatives from the Pentagon and t…