A forensic psychiatrist who interviewed Graham Weich told John's courtroom that the 21-year-old killed David Collins because he believed it was the right thing to do.
Dr. Nazir Lada, who interviewed the accused and examined the statements of several family members, policemen and acquaintances, said Vachech is showing classic symptoms of schizophrenia.
"Graham did not appreciate the nature and consequences of his actions," said the psychiatrist at the Supreme Court on Friday.
Weich faces charges of second-degree murder in the death of Collins, his mother's partner.
The agreed statement of facts, introduced in March, describes how Weich killed 55-year-old Collins, a well-known pharmacist, after another typical night in the family home of the Kadigan Road in Lodz Bay-Med Kau-Outer.
Vejic is 18 years old on December 18, 2016, when dinner with his mother, Joan Weich and Collins.
Then he went upstairs and his mother and Collins sat down in the living room. A little later, Waits came back downstairs, stood behind a sitting Collins and hit him with a hammer many times.
Lada has been summoned to testify by Veitch's lawyers who claim he is not criminally responsible for mental disorders.
Veic, who was detained after the murder, had delusions about Collins, Dr. Lada told the court.
During the interview, the doctor said Veitch had told him that Collins would kill him, and his mother and brother were also in danger. Veitch told the doctor that he received messages from demons and that he had been "persecuted" by Collins.
Other witnesses told the police that Collins was a passive person with whom it was easy to understand, but Weich said he felt so threatened he had decided to kill his mother's partner.
"In a sense this is a quick decision," Lada said. However, he added, "his perception of Dave has been produced over time."
Lada has said that any Watsch's symptoms can be explained by other factors, but taken together in the context, they show a clear syndrome.
"So, yes, that's schizophrenia.
Vejic is also accused of assaulting his mother, attacking a police officer, stealing a car and hiding the police after the murder.
His case goes on May 27th.
Read more from CBC Newfoundland and Labrador