TORONTO -- A woman charged in an apparently unprovoked fatal stabbing in Toronto's financial district late last year has been ordered to undergo a mental health assessment.

Rohinie Bisesar's lawyer says the assessment -- which will examine his client's fitness to go through the legal process -- was ordered on Friday after the 40-year-old woman exhibited "bizarre" behaviour in public court.

Bisesar is charged with first-degree murder in the death of 28-year-old Rosemarie Junor.

Junor, a newlywed medical technician, died several days after being stabbed at a Shoppers Drug Mart in Toronto's popular underground PATH network of shops and restaurants on Dec. 11.

Security images taken at the time of the stabbing showed a well-dressed, long-haired woman making a hasty retreat from the drugstore.

Bisesar was the subject of a manhunt for several days before her arrest.

Her lawyer, Calvin Barry, said Bisesar had been seen by a psychiatrist in jail since her arrest and her fitness to participate in her case was not an issue until recent court appearances.

"She started exhibiting bizarre behaviour in open court, talking over the judge," he explained. "We now have some concerns, as does the judge, as does the prosecutor, as to her fitness because of the rants."

Bisesar has spoken out about hearing voices, Barry said, and has also expressed concerns about being implanted with something.

She was also recently admitted to hospital for a week under the Mental Health Act after exhibiting troubling behaviour at the detention centre she's being held at, Barry said.

Bisesar's case was transferred to a mental health court on Friday, where Barry made a request for the fitness assessment, which was granted by a judge.

Bisesar is now set to be assessed at the Centre for Addiction and Mental Health in Toronto next Tuesday, and her case is to be back in court May 4, Barry said.

Bisesar was originally charged with attempted murder, but that was upgraded to second-degree murder and eventually to first-degree murder in February.

Barry said his client's case was still in its early stages.

"It's tragic all around," he said. "It's always a bit more problematic when you have a mental health issue in a matter before the court."