He joined the army last year with the express purpose of committing jihad, but was discharged after threats he made on Facebook went public last year.

A 20-year-old Kansas man plotted to kill American soldiers with a vehicle bomb at the Fort Riley military base, an attack he planned to carry out on behalf of the ISIS terror group, prosecutors announced Friday.

John T. Booker, also known as Mohammed Abdullah Hassan, was arrested as part of a lengthy FBI investigation. Federal authorities said he was arrested near the army base in Manhattan, Kansas, as he completed final preparations to detonate the bomb, which had, in fact, been rendered inert while he was under FBI surveillance.