Vendors at a Sunday flea market say they were surprised to find out that the man shot by Calgary police in a downtown alleyway was one of their own.

The man, Morgan Thompson, regularly manned a booth at the Hillhurst/Sunnyside flea market with his father, CBC News has learned.

“He's been a decent kid, I've never had any run-ins with him or heard of anyone else having any run-ins with him,” said  William Basque, who has known Thompson for decades.

“What happened to Morgan is just a complete shock to everyone here.”

Thompson was shot on Saturday, shortly after confronting people gathered at an anti-racism rally near city hall. Witnesses report Thompson was agitated and repeatedly shouted “white power” at the group.

Police say Thompson was followed by officers into an alleyway where there was a confrontation.

“There was brief physical contact, we do know the officer drew his baton, which was recovered on scene,” said Susan Houghton, who is with Alberta’s Serious Incident Response Team (ASIRT).

Thompson allegedly threatened the officer with a pipe, according to ASIRT, and was shot.

He was taken to hospital. People at the market say they have been told he is in grave condition.

Richard Greene, another vendor at the market, said many are eager to learn more about what led up to the shooting.

“We're all flabbergasted … we just don't know what to say,” he said. “For someone like that to be involved in that, it just doesn't make any sense at all.”

ASIRT continues to investigate. Anyone with information about the incident is asked to contact Calgary police.