Luka Magnotta knew what he was doing — but did not know it was wrong — on the night he killed 33-year-old Jun Lin, says the psychiatrist who concluded the accused was in a psychotic state on May 25, 2012.

Forensic psychiatrist Dr. Marie-Frédérique Allard examined Magnotta for 23 hours over numerous days to come to her diagnosis, and she had access to extensive witness testimony, video entered into evidence and medical files.

"Mr. Magnotta suffers from schizophrenia; that illness was present on May 25, 2012, and it is responsible for the five charges against him," Allard told the court.

Allard explained there are two aspects to determining if someone is criminally responsible or not.

She concluded that Magnotta knew what he was doing — for example, by using a knife — but that his perception of whether this was right or wrong was skewed, since he had lost contact with reality because of his psychosis.

Allard told the court Magnotta was one of the most difficult patients she’s ever had to examine, because he tends to minimize his symptoms, which he prefers not to discuss.

"He doesn’t think he is as sick as he is," Allard testified, adding that in her opinion, "it’s clear" Magnotta suffers from schizophrenia.

Fear of stigma

The psychiatrist said Magnotta was marked by his father’s schizophrenia and did not want to appear sick for many years so he would not be stigmatized.

Allard also declared that Magnotta was in a position to easily simulate the symptoms of a mental illness because he was so familiar with them, but for her "it’s clear" he suffers from schizophrenia.

The psychiatrist detailed the ways some patients fake symptoms, and told the court one sign of embellished hallucinations is a patient who claims to hear voices continually, when most people with schizophrenia hear voices in their heads intermittently.

Allard also walked the court through medical records from a Peterborough, Ont., hospital that Magnotta visited three times in 2001.

Magnotta, who was 18 at the time, was referred there by workers at a nearby crisis centre, who suspected he was making up hallucinations.

One crisis worker told a doctor that "the impression is that he is schizophrenic, however whenever [the worker] has talked to him, she has come up with an impression that he is sort of making up his problems."

Allard pointed out that the late teenage years and early 20s mark the prime age for males to begin showing signs of schizophrenia and it often takes months or even years for a clear diagnosis.

Records also show that Magnotta was rushed to emergency a few months later after swallowing an entire bottle of anti-anxiety medication.

Allard told the court it’s not uncommon for patients suffering from schizophrenia to attempt suicide, especially when symptoms first begin to show.

Magnotta was living at a home for people with mental illness. He didn’t like it and felt isolated, Allard added.

Magnotta developed crush on nurse

The court heard earlier in the day that in April 2013, Magnotta developed a crush on a male nurse who was friendly and complimentary with the patient.

Magnotta interpreted the nurse’s behaviour as a sign of possible attraction, and sent him a “pretty crude” letter, Dr. Renée Roy, the accused’s current treating psychiatrist, testified.

Magnotta also created mood lighting in his cell, hoping the nurse would visit, and was disappointed and anxious when the detention centre’s administration found out his intentions and transferred the nurse to another department.

Crown prosecutor Louis Bouthillier asked whether it’s surprising for patients with mental health problems to have similar romantic or sexual desires and Roy responded that it was not unusual.

Roy also testified that, at first, Magnotta hid the fact he was hearing voices, which the psychiatrist explained came from the patient’s fear he would be placed in isolation as a result.

The prosecutor asked if Magnotta filtered the information he provided, choosing when to speak up about symptoms.

Roy replied many of her patients do the same.

The defence is presenting its case that Magnotta should not be held criminally responsible for killing Lin.

Magnotta has admitted to the physical acts behind the five charges he faces, but has pleaded not guilty.

The Crown alleges the killing was premeditated.

Allard's testimony continues on Monday morning.