Even in my religion. The Catholic Church is opposed to executions, except where the State is incapable of preventing a killer from killing again.
The documents they produced sure look like conspiracy to torture. A conspiracy that resulted in people being killed. That is a death penalty crime under US law.
Perhaps they think they are heroes, warriors in a clash of religions and cultures. But they are criminals. Like those other criminals who want to be seen as warriors, they deserve trials in Federal courts. Unlike those other criminals, these have powerful accomplices likely to release them so they can kill again. There is a moral reason to seek the death penalty - mere imprisonment will not stop them.
They apparently did their alleged crimes knowing that innocent people would die horribly as a result. Just like those other guys.
Unlike the other guys, they used the power of the US government and claimed to be acting for us. They dishonor us. They bring shame on the Republic. They couldn't befoul the flag more if they used it as toilet paper.