Canada's worst mass shooting in history was triggered by a domestic dispute between the gunman and his girlfriend, a police official has said.
Gabriel Wortman killed at least 22 people across northern and central Nova Scotia on Saturday and Sunday, but his partner survived the attack.
Speaking ahead of a news conference in which more details were expected to emerge, a police source told the Associated Press that the killings began after a domestic dispute between the pair.
The shootings happened across 16 crime scenes in five rural communities.
Wortman, 51, was shot dead on Sunday morning, around 13 hours after the attack started.
Police said several bodies were found inside and outside one home in the rural town of Portapique.
Authorities believe the gunman targeted his first victims before launching a series of random attacks as he drove around disguised as a police officer, in a vehicle marked to appear like a patrol car.
Officials say he shot people in and around their homes and set fire to homes in Portapique.
The owner of a denture practice in the city of Dartmouth, near Halifax, Wortman lived part time in Portapique, residents say.
His practice, Atlantic Denture Clinic, had been closed for a month due to the coronavirus pandemic.
Authorities said Wortman did not have a police record, but it later emerged he had had at least one run-in with the law.
Court records show he was ordered to receive counselling for anger management after pleading guilty to assaulting a man in the Halifax area in 2001.
Canada has had relatively few mass shootings, having overhauled its gun control laws after Marc Lepine killed 14 women and himself at Montreal's Ecole Polytechnique college in 1989.