See thats the problem, we all know he's the guy who did it. There is enough open source intelligence and evidence that any court of law would find him guilty, that should be used to the fullest. The problem comes from the evidence gathered while he was tortured and from evidence gathered by secret sources and methods. Traditionally for evidence to be considered it has to have a long history behind it, police officers have to take logs of exactly where and when it was found, and every single person who handled it, and where it was every moment of every day until its brought to trial. The problem with evidence gathered with secret methods, the sources and methods cannot be revealed for national security reasons, which I understand. But basically because the other members of the court are not capable of seeing how this evidence was gathered they have to trust information from a single source which they cannot verify.
The real question is how much do we want to reveal, or do we want to reveal anything at all, during a trail and how will these trails, with secret evidence, be different than others?
Torture isn't needed anywhere in here.