KANSAS CITY, Kan. (AP) — A 21-year-old Topeka man who has pleaded not guilty to federal charges that he plotted to bomb Fort Riley in support of the Islamic State group wants to change his plea.

John T. Booker Jr. filed a motion Wednesday in Topeka, asking for a change-of-plea hearing. A judge has scheduled that for Jan. 12.

A message left Thursday with Booker’s public defender, Kirk Redmond, wasn’t immediately returned.

Booker is charged with attempting to use a weapon of mass destruction, attempting to use an explosive device and attempting to provide material support to a terrorist group.

Court documents show Booker was arrested in April while trying to arm what he thought was a 1,000-pound bomb inside a van near Fort Riley, about an hour west of Topeka.