Are we sure these witnesses are for the prosecution?
Strange though it would appear, I think on the whole the teacher and head teacher provide a narrative of a boy who is generally well behaved, has a narrow range of interests but will sit quietly when not interested and is a poor verbal communicator.
If he had no concept of right from wrong would he not be disruptive and have poor conduct? I suggest the prosecution are demonstrating that this child behaved because he knew what was and wasn't acceptable in a group context.
Although the doctrine of doli incapax was abolished in 1998, this evidence is demonstrating that he is capable of forming the intent to commit a crime because his moderate behaviour shows us that he knows right from wrong. The teachers/head teachers evidence that they had never been privy to an incident when they had to question his ability to understand right from wrong further supports my assertion.
He is strong for his age, a good walker, he enjoys being outdoors. Obvious, I know, but they are attributes that support the killers MO. Because of these the defendant is probably very well acquainted with the local geography of the Coppice, Hillock Vale and the cemetery, all of immense benefit when stalking for a victim before attacking, moving, concealing and disposing of them.
As has been said in this thread, with the defendants limited verbal communication, could he realistically have engaged with an unknown third party in a way that they would be confident that he understood their request and would carry it out successfully?
We know his defence doesn't hold water but nevertheless it is his defence and this element of the evidence supports a view that he would be unable to negotiate such a contract.
The teacher said that he was compliant and easily led. I don't believe that any examples were given of when he has been easily led in a gullible or naive way. They did say if he didn't want to do something that he just said "no" and didn't do it. That doesn't strike me as being exceptionally compliant and acceding to any request, no matter how wrong.
So there you have it. I feel that the teachers are definitely worthy witnesses for the prosecution.
Just my opinion of course.