After the Toronto shooting I expected there to be an outcry that Canadians were illegally getting guns from the U.S. While this undoubtedly is happening the Canadian Broadcasting Company ran this article saying Canadians, selling guns to other Canadians is a big source of guns used in crime.
https://www.cbc.ca/news/canada/toronto/guns-domestic-danforth-shooting-toronto-1.4759159
https://www.cbc.ca/news/canada/toronto/guns-domestic-danforth-shooting-toronto-1.4759159