Defense Secretary Jim Mattis on Monday fired the top official overseeing the trials of five men being held at Guantánamo Bay who have been accused of plotting the 9/11 attacks.

Harvey Rishikof is an attorney with experience in national security law, but with no military experience. According to the Miami Herald, there is no known reason for Mattis’ decision to fire the man he named convening authority for military commission last April.

Two Pentagon lawyers have replaced Rishikof and Gary Brown, a legal adviser for military commissions who was fired by acting general counsel William S. Castle.

Tom Crosson, a spokesman for the Department of Defense, said the two men were removed from their positions on Monday.

President Trump has been critical of the speed at which trials by military commission moved. On Nov. 2 he tweeted that he wanted to send a suspected terrorist to Guantánamo, but it would take “much longer than going through the federal system.”

Rishikof was at the center of multiple controversial decisions, like suspending chief defense counsel Marine Brig. Gen. John Baker, and rejecting a proposed charge sheet for three former CIA captives suspected of plotting terror attacks.