A Grand Forks, B.C., woman has pleaded not guilty during the start of her second-degree murder trial in the death of a 12-year-old autistic boy.

The body of John Fulton was found in the townhouse of Kimberly Ruth Noyes on August 17, two days after he disappeared from the front steps of a neighbouring home.

Yesterday, the B.C. Supreme Court in Rossland, in the southern Interior, was told the boy was killed as a result of a stab wound to his neck.

Defence Lawyer Deanne Gaffar says Noyes is mentally ill and cannot be held criminally responsible for her actions. But the Crown intends to argue Noyes knew what she was doing.

A statement of fact entered by the Crown Monday revealed Noyes told police she'd stopped taking her medication for bipolar disorder two weeks before the slaying.

Police, doctors and friends of Noyes are expected to testify in the case.

Noyes is being tried by judge alone.