TORONTO -- A man had been spending time with friends when he was stabbed to death inside an apartment late Saturday night, Toronto police said Sunday as they called on witnesses to come forward.

Ian Dyer, 36, is the city's first homicide victim of the year.

Officers were called to reports of a stabbing at about 12:30 a.m. on Sunday and found Dyer with serious injuries, said Det. Paul Worden said.

He said investigators believe Dyer was stabbed inside an apartment on the 12th floor of a Toronto Community Housing building sometime between 11:30 p.m. and midnight.

Emergency services tried to save the man's life, but he died at the scene.

Worden said it wasn't clear whether officers should be looking for one suspect or multiple, noting that they were still in the process of reviewing security footage and canvassing the building early Sunday afternoon.

He said they're trying to piece together the last days and hours of Dyer's life, and asked anyone with information to come forward.

So far, investigators have gleaned that Dyer had been staying with friends in the east-end building for a few days before his death.

"It's my understanding that the building has had a troubled past. Unfortunately violence is not uncommon there," he said, noting that the 12th floor in particular is known for drug activity.

Worden said Dyer was known to police, but officers do not believe the man or his friends were engaged in any criminal activity before the stabbing.

"He was in the apartment with friends, and everything was fine, according to the people who were last with him," Worden said, adding that it appears that when Dyer was killed, his friends had left the apartment.

"That's based on witness interviews with the people who were with the victim previously, and the people who found him and called in," Worden said.

"The surveillance video will play a big part. We're going to use that to generate any potential leads and suspects, and also use it to corroborate the accuracy of what we've been told by certain witnesses," he said. "We want to make sure the information we've been provided is accurate and truthful."