Marie-Frederique Allard was hired by the defence to determine Magnotta's criminal responsibility, which is central to his defence in his first-degree murder trial.
She consulted evidence and medical records and saw Magnotta personally for about 25 hours over several meetings, beginning in December 2013.
He has admitted to killing the 33-year-old Chinese engineering student in May 2012, but has pleaded not guilty by way of mental disorder.
Magnotta faces four other charges: criminally harassing Prime Minister Stephen Harper and other members of Parliament; mailing obscene and indecent material; committing an indignity to a body; and publishing obscene materials.
Allard told the jury this afternoon she believes Magnotta was suffering from schizophrenia when he killed and dismembered Lin. She says Magnotta's perception of reality was skewed in the commission of all five offences with which he is charged.
"He was capable of judging the nature and quality of his actions," Allard said, adding he was not able to rationally apply the notion of right and wrong to those actions.
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