SASKATOON -- In a vital component of the defence’s not criminally responsible case, the forensic psychiatrist who assessed Blake Schreiner’s mental state took the stand.

Foresnic psychiatrist Dr. Mansfield Mela testified Schreiner was battling schizotypal personality disorder at the time he stabbed his spouse.

Tammy Brown was found with 80 stab wounds all over her body in the couple’s Saskatoon home on Jan. 29, 2019.

Schreiner has pleaded not guilty to first-degree murder.

The Crown is arguing Schreiner planned Brown’s death, while the defence is trying to establish Schreiner’s mental state rendered him incapable to appreciate his actions.

Mela diagnosed Schreiner with schizotypal personality disorder following two five-hour interviews with Schreiner, and after reading his journals.

People with schizotypal personality disorder are often incompetent in social settings and can believe their “thoughts or wishes have power,” Mela told court.

“Not only did he believe things, but he acted on them,” Mela testified, referencing Schreiner’s decision to flee to different cities out of fear.

“He believed he was in grave danger by many many sources … His judgement was impaired.”

Earlier in the trial, Schreiner told court he heard voices in his head and believed Brown was trying to kill him. He said he thought Brown was designing his coffin during the renovation of their closet.

Defence lawyer Brad Mitchell asked Mela whether he thought Schreiner was able to appreciate the nature and the consequences of his actions.

The Crown objected to the question, but the judge allowed Mela to answer.

“He did not know what he was doing was wrong,” Mela testified.

Putting rationality aside, Schreiner believed he was in harm’s way and stabbing Brown was the only option and the right option, Mela said.

While Schreiner testified hearing voices leading up to the stabbing, Mela said hearing voices is not an inherent symptom of schizotypal personality disorder, but can be triggered by stress.

Schreiner was also diagnosed with social anxiety disorder and substance abuse disorder, court heard.

In Mela’s first interview with the accused in July 2019, Schreiner said he was under the influence of of psilocybin, known as magic mushrooms, while stabbing Brown.

In the second interview, in November 2019, Schreiner said he was actually sober the evening of the killing.

Mela said even if Schreiner was on mushrooms, most people realize their hallucinations aren’t legitimate and Schreiner had “crossed over to the psychotic path.”

Schreiner’s trial had been adjourned due to COVID-19 but is scheduled to continue all week.

On Tuesday, the Crown is expected to cross-examine Mela.