George Washington wouldn’t let Major Andre face the firing squad as he requested. He was a spy and was hanged accordingly. These terrorists deserve less.
That question also came up at Nuremberg. The defendants thought being shot was a more dignified way to die. But ultimately the job went to Master Sergeant John C. Woods, 43, of San Antonio, an experienced hangman. Ten men in 103 minutes (Goering got a hold of some cyanide and did himself in a few hours before he was scheduled to hang).