TORONTO – Police fanned out across more than a dozen crime scenes Monday after a rampage by a gunman disguised as a police officer left at least 18 dead and homes in smoldering ruins in rural communities across Nova Scotia — the deadliest mass shooting in Canada's history.

Officials said the suspect, identified as Gabriel Wortman, 51, also died in the attack. Authorities did not provide a motive for the killings, but they believe he acted alone. RCMP Commissioner Brenda Lucki said he was not well known to police.

Royal Canadian Mounted Police Chief Superintendent Chris Leather said Monday that police teams were spread out at 16 locations. He said some of the victims knew Wortman and some didn't. Leather said they expect to find more victims once they are able to comb through all the crime scenes, some of which were houses set ablaze as victims were inside, adhering to government calls to stay at home because of the coronavirus pandemic.

The dead included a policewoman. Another officer was wounded and was recovering at home, Leather said.

"The 18 innocent lives lost will be remembered throughout Canada's history," Public Safety Minister Bill Blair said.

Canadian Prime Minister Justin Trudeau noted how close-knit the small province of Nova Scotia is. "The vast majority of Nova Scotians will have a direct link with one or more of the victims. The entire province and country is grieving right now as we come to grips with something that is unimaginable," he said.

The 12-hour rampage began late Saturday in the rural town of Portapique, about 60 miles north of Halifax, where police warned residents to lock their doors and stay in their basements as the attack unfolded.

Several bodies were later found inside and outside one house on Portapique Beach Road, the street where the suspect lived, authorities said. Bodies were also found at other locations within about a 30-mile area, and authorities believe the shooter may have targeted his first victims but then began attacking randomly.

Authorities said the gunman wore a police uniform and made his car look like a Royal Canadian Mounted Police cruiser. "His ability to move around the province undetected was surely greatly benefited by the fact that he had a vehicle that looked identical in every way to a marked police car," Leather said, adding that the gunman was also either wearing a police uniform or very good copy.

He said at one point the suspect was forced to abandon his car and then carjacked other vehicles to continue to "circulate around the province steps ahead of our investigators."

According to his high school yearbook, Wortman long had a fascination with the Mounties. "Gabe's future may include being an RCMP officer," his profile said.

Wortman, who owned a denture practice in the city of Dartmouth, near Halifax, lived part time in Portapique, according to residents. Atlantic Denture Clinic, the practice Wortman owned, had been closed for the past month because of the coronavirus pandemic.

The dead officer was identified as Constable Heidi Stevenson, a mother of two and a 23-year veteran of the force.

Elementary teacher Lisa McCully also was among the dead.

Two health care workers at nursing homes were also among those killed, according to Von Canada, a long-term health care company, which identified them as Kristen Beaton, a continuing care assistant, and Heather O'Brien, a licensed practical nurse.

O'Brien's daughter, Darcy Dobson, wrote in a Facebook post that, "A Monster murdered my Mother."

"Murdered her, without a second thought. … At 9:59 a.m. she sent her last text message to our family group chat. By 10:15 she was gone."