Police charged Brian Dickson, 29, with the first-degree murder of Qian Liu, a 23-year-old Chinese national who was studying English at York University.
Liu was killed Friday morning when she let an unidentified man into her room while chatting online with her boyfriend in China, according to police.
The boyfriend, identified Wednesday as Meng Xianchao, told police there was a knock at Liu's door around 1 a.m. ET Friday and a man asked to borrow her cellphone.
Xianchao witnessed "a struggle between the deceased and the man," according to police, before the suspect shut off her computer and stole the laptop. Also stolen were her cellphone and the webcam she was using to chat with her boyfriend.
Liu's boyfriend immediately used the Internet to raise people he knew in Canada who could alert the police. He contacted Liu's family in Beijing, who called the Chinese consulate in Toronto. But it was almost 10 hours after the intruder knocked on the door that police finally entered Liu's apartment and found the woman dead.
Liu was found naked from the waist down, but there were no signs of sexual assault, according to police.
Police interviewed Xianchao over the phone, who described the intruder as a white male, 20 to 30 years old, 175 to 200 pounds, with "medium-length brown hair, messy at the front and well-groomed at the back."
Deadly Assault Witnessed on Webcam
Police did not say whether Liu knew Dickson, but said Tuesday they were investigating a person of interest. On Toronto's Chinese-language message boards, that person was rumored to be a spurned paramour who was "stalking" Liu.
"The suspect once shared the same house with Liu," the friend wrote anonymously online in a Toronto-based Chinese-language chat room, according to the Toronto Star.
"The suspect was chasing after her, but she refused, then he started stalking her by texting her all the time," the friend wrote.
Police said Liu had never reported any harassment to police and, as far as they could determine, had likely not been stalked.
Liu arrived in Canada in September 2010.
Her family is expected to arrive in Toronto today or Thursday.
Liu death appears to be the first time that a murder has been witnessed on the internet, although there have been instances of suicides carried out live on the internet.
In 2009, Mohamed Hossain, received a frantic call from his 21-year-old daughter's boyfriend that the young woman had just attempted suicide inside the family's Tucson, Ariz., home. The boyfriend, living in Michigan, watched via the Internet as the woman hanged herself from a ceiling fan.
A year earlier, Abraham Biggs, 19, of Pembroke Pines, Fla., livestreamed his suicide over the internet as commenters egged him on and called him names. Biggs overdosed on sleeping pills and laid motionless for several hours as the broadcast continued. Viewers realized Biggs was not joking when they watched paramedics storm his bedroom.