The woman accused of an unprovoked stabbing at a downtown Toronto drug store is now facing a charge of murder, after the victim in the attack died of her injuries.

The Toronto Police Service announced Thursday afternoon that the charges against Rohinie Bisesar, 40, have been upgraded to second-degree murder. The homicide squad has now taken over the investigation.

The victim in the case, Rosemarie Junor, 28, died Wednesday night; her death was announced early Thursday morning.

The stabbing occurred last Friday, Dec. 11, at a Shoppers Drug Mart in Toronto's PATH network, an underground pedestrian walkway and shopping complex that links 30 kilometres of stores.

Junor’s brother, Richard Junor, spoke with CTV Toronto and said that his sister was a “very kind, loving, caring person who was so energetic.”

“It was something, I mean, you walk into a room and she brightens everything,” Junor said about his sister.

Investigators say a woman went into the store armed with a knife, approached the victim and stabbed her without provocation. She was rushed to hospital with what were described as life-threatening injuries.

The victim, who also went by her middle name of Kim, worked at a Medcan clinic in Toronto.

“We are shocked and greatly saddened by this senseless tragedy, which took the life of our colleague. Our organization is like a big family and we are all grieving today for this loss,” the clinic said in a statement released on Thursday.

“Rosemarie was just such a vibrant, happy and glowing person. She had so many good friends here, and was such a positive force here, and we are all just devastated. Our thoughts and prayers are with her family.”

Bisesar's lawyer Calvin Barry said Wednesday that his client has an "impressive resume," including an MBA, as well as numerous friends who said the allegations were not in her character.

Barry was also asked about an email sent to the National Post on Tuesday, just minutes before Bisesar was arrested, but he said he couldn't comment. The email was written by someone from an email address matching Bisesar's name.

"Something has been happening to me and this is not my normal self," the email read.

"I would like to know who and why this is happening. There is either a single person or more responsible and who and why would be nice to know."

The email sender also wrote: "I am sorry about the incidence (sic). I felt the need to be extreme to see if it would work. I would normally not do such a thing."