Alexander Blair, 29, pleaded guilty to one count of conspiracy for helping his friend, store equipment to make a bomb.
Alexander Blair, 29, pleaded guilty to one count of conspiracy for helping his friend, John Booker Jr., store equipment to make a bomb to kill American service members, prosecutors said.
Blair admitted that he and Booker plotted to detonate a vehicle bomb at Fort Riley military base near Manhattan, Kansas.
Prosecutors said that after Blair was arrested and was asked about the plan to kill service members, Blair said: "That's what they signed (up) for."
Blair's attorney Chris Joseph said his client has a genetic condition, Williams syndrome, that made him easily manipulated and unable to appreciate the gravity of his conduct. A defense expert testified that he functioned at the level of an 11-year old.
Joseph said he appreciated that the judge in the case saw the government's demand for five years in prison as overreaching. He said no decision has been made yet on whether to appeal.
Blair's co-defendant Booker, 22, made statements on Facebook and to FBI agents that he wanted to join Islamic State and kill people and was willing to die in the process, according to prosecutors.
He was arrested on April 10 in a sting operation in which he went to Fort Riley with two undercover FBI agents to detonate what he did not know was an inert bomb, prosecutors said.
Booker pleaded guilty to one count each of attempting to use a weapon of mass destruction and attempting to destroy government property with an explosive, according to court documents. He is awaiting sentencing, but has agreed to spend 30 years in prison in the plea deal.
According to court documents, Blair and Booker shared extremist views in support of Islamic State and against the U.S. military.