What should be done with Khalid Sheikh Mohammed? If the Defense Department is to be believed, the chief planner of the 9/11 attacks on America is guilty of mass murder and crimes against humanity. Even if the evidence elicited by waterboarding him 183 times is void, his declaration in 2002 that “I was responsible for the 9/11 Operation from A to Z” should ensure conviction.

In addition to the 9/11 attacks that killed 2,973, he is credited with commissioning shoe-bomber Richard Reid to down a transatlantic jetliner laden with 300 passengers; planning the 1993 attempt to fell the Twin Towers, the Bali nightclub bombing that killed 200 and a bomb attack in Istanbul in 2003 that killed 60; as well as plots to assassinate Pope John Paul II and Bill Clinton and to demolish the Empire State Building and the Brooklyn Bridge. For those who would argue Mohammed is a war combatant rather than a dangerous psychotic, it should also be noted that he personally sawed off the head of the American reporter Daniel Pearl.

Mohammed and his co-conspirators face the death penalty, but it is by no means certain the prosecution will ask for it. There are a number of practical reasons Mohammed should instead live out his days buried in the vaults of a maximum security prison. He desperately wants to end his days of idle impotence and emerge as an inspirational figure in the Islamist war against the West. “This is what I wish, to be a martyr for a long time. I will, God willing, have this, by you,” he explained in 2008. He would be sooner forgotten alive than dead; just think of Charles Manson.

Moreover, Mohammed remains a key source for understanding al Qaeda’s modus operandi and its next moves. He has been spilling the names and whereabouts of sleeper cells, and it was his information that led to the discovery and death by Navy SEAL of Osama bin Laden. Better alive and singing than taking his secrets to the grave.

Demanding the death penalty would also entail a far longer trial, giving Mohammed more opportunities to have his remarks in court relayed to his followers. A capital sentence would open up a lengthy avenue of appeals, keeping him and his murderous creed in the headlines. Asking for life imprisonment would cut that short.