Video captured by a bystander shows Vancouver police opening fire on a suspect who they say stabbed "a number of people."
Police say the violent incident happened in the downtown core, near the city's main library.
A video obtained by The Canadian Press shows officers aiming their guns inside a convenience store and firing at least 10 times.
A stun gun held by an officer appears to have already been fired, with the wires trailing over the counter inside the 7-Eleven store.
"Move over, right now. Move over," one officer shouts at the unseen suspect before gunfire is heard.
Another video shows two people being wheeled away on stretchers, with a firefighter performing chest compressions on one of them.
Mainul Islam, a student and part-time delivery worker who captured the shooting scene on video, says he was stopped by police from entering the store before witnessing the shooting of a man he described as "homeless."
After the shooting, a man can be heard saying "are you OK ma'am?" while a woman sobs.