A 17-year-old boy accused of murdering a teaching assistant in Lancashire was described in court as "easily led".
Lindsay Birbeck, 47, was found dead in Accrington Cemetery 12 days after she went missing on 12 August.
The defendant, who cannot be named for legal reasons, denies murder but admits burying the body for a stranger who promised him "a lot of money".
The teenager's former teacher told Preston Crown Court he was "very quiet" and "withdrawn".
He struggled to communicate with others due to ADHD and autism, according to the teacher.
He would only answer "yes, no or don't know" or shrug his shoulders to questions, jurors heard.
The witness also agreed the boy was towards "the bottom of the educational scale" but did not appear stressed at school and was not violent.
"I never saw any aggression from him towards me or the other pupils," he said.
The defendant was "strong-willed enough to say no to something, if he really didn't want to do it", the court heard.
Jurors have heard Mrs Birbeck was last seen heading towards an area known locally as The Coppice.
Despite extensive searches her body was not found until 24 August.
Preston Crown Court also heard from Zoe Braithwaite, who entered The Coppice about 20 minutes before Mrs Birbeck.
She said she noticed a lone male figure on a parallel path.
Mrs Braithwaite said: "I had decided that whichever way he went I would take another route because, from the first time I saw him, I was wary of him. He looked out of place in the woods."
The trial continues.