Ammar al-Baluchi says the US wants to prosecute him using statements he made under torture, asks for a UN investigation.

I don't think the US is likely to grant that.

The US should release all the prisoners in Guantanamo prison. Even if some of them really did commit terrorism, they have been punished enough. It is wrong to punish people without trial, and in order for the US clear its name, it has to stop doing this.