John Bolton, who served as national security adviser during President Trump's first term before becoming a vocal critic, was indicted on Thursday on 18 charges related to the mishandling of classified documents.

Details from the indictment filed in Maryland's district court charge Bolton with eight counts for the transmission of national defense information and 10 counts of unlawful retention of such information. Each count faces a maximum of 10 years in prison.

In a statement, the Justice Department said Bolton illegally transmitted classified information using a personal email and messaging applications, including U.S. "intelligence about future attacks, foreign adversaries, and foreign-policy relations."