Federal court documents show that a 29-year-old Topeka man plans to plead guilty to a conspiracy charge in connection with a plot last year to bomb the Fort Riley military base.

Alexander E. Blair’s attorney filed a request Thursday to change the not guilty plea entered for him last year by a federal magistrate. A change-of-plea hearing is May 23.

Blair is charged with helping 21-year-old John T. Booker Jr. of Topeka in planning to plant a bomb outside the Army installation in northeast Kansas to aid the Islamic State group. Blair could face up to three years in prison.

Booker pleaded guilty in February to two charges under an agreement with prosecutors calling for him to spend 30 years in prison. He has not yet been sentenced.