The defendant, Ari Da Costa, brought a mistrial application during his jury trial for first-degree murder, arguing that his right to a fair trial was irreparably compromised due to an eleventh-hour change in opinion by a key Crown forensic psychiatrist, Dr. Klassen.
Dr. Klassen, initially a Crown witness who did not support an NCR defence, provisionally changed his diagnosis to schizophrenia after reviewing extensive new records.
The court found that this significant change in expert opinion, coupled with the necessity of a lengthy adjournment to allow Dr. Klassen to finalize his report, would unduly prejudice the defendant by making it impossible for the jury to retain the nuances of the defence expert testimony.
The court granted the mistrial application, emphasizing the paramount importance of a fundamentally fair trial.
