"We know that Mr Kumar died, but that was never anticipated, planned or contemplated by [the accused]," she said.
Ms Kincade said the court will hear from a clinical neuropsychologist, Dr Valerie McGinn, who works primarily with children.
Dr McGinn will testify about the state of mind of the accused.
Ms Kincade told the jury that the doctor has spent time analysing the boy's history, and will tell the court he suffers from a brain injury.
"Dr McGinn will tell you about the types of tests she has administered, and her interpretation of the results of those tests, based on prior knowledge and experience," said Ms Kincade.
The defence has also called a video analyst and members of the boy's family to testify in his defence.
- Newstalk ZB