2020 Nova Scotia attacks

On April 18 and 19, 2020, 51-year-old Gabriel Wortman committed multiple shootings and set fires at 16 locations in the Canadian province of Nova Scotia, killing 22 people, and injuring three others before he was shot and killed by the Royal Canadian Mounted Police (RCMP) in the community of Enfield. The attacks are the deadliest shooting rampage in Canadian history, exceeding the 1989 École Polytechnique massacre in Montreal, where 14 women were killed.

Police were criticized for not using Alert Ready to warn the public about the unfolding attacks, as well as not responding to reports of Wortman's previous behaviour and acts of violence. An investigation into law enforcement's response to the rampage, including the decision not to use Alert Ready, was launched. A public inquiry into the law enforcement response was declared on July 28, 2020, following escalating criticism of the investigation's lack of transparency.

On May 1, 2020, in the wake of the attacks, Prime Minister Justin Trudeau, following through on a 2019 campaign promise, announced an immediate ban on some 1,500 makes and models of "military-grade assault-style" weapons, including two of the five guns used in the attacks. The ban included the Ruger Mini-14, which Wortman obtained illegally within Canada, while the other four guns he used included a stolen Smith & Wesson 5946 handgun from an RCMP officer who he killed and three guns smuggled in from the United States.