"Relevance?"

If this is true, it is relevant. Asperger's is not always easy to diagnose and sufferers can and do lead relatively normal lives, often un-noticed and untreated. They are often adept at very technical work requiring high analytical skills, but often they have some 'eccentricities', in the form of varying degrees of problem with social interactions. If this chap has Asperger's then the chances are however you explain the wrongs of his actions he won't see it that way.

Of course, as the US actually condones the killing of mentally ill people then actually suffering from a disorder isn't a defence.

But then extraditing an individual to any county that carries the death penalty, kidnaps, tortures and detains people without trial and without access to proper legal support is morally unacceptable in my opinion anyway.