Open this photo in gallery Wentworth volunteer firefighters douse hotspots as an excavator digs through the rubble of a destroyed home linked to Sunday's deadly shooting rampage on April 20, 2020, in Wentworth Centre, N.S. Tim Krochak/Getty Images

On an overcast Nova Scotia morning, flags fluttered at half-mast and memorials sprouted up like flowers, as families and friends learned of losses, a province grieved, and a country struggled to comprehend the staggering toll of Canada’s deadliest shooting.

RCMP now say there are “in excess of 19 people” dead, and that number is expected to rise further. Police are investigating, and also mourning one of their own, RCMP Constable Heidi Stevenson, who was killed in the attack.

“I know this is a challenging time for Nova Scotians and that there are so many unanswered questions,” RCMP Chief Superintendent Chris Leather said at a press conference in Dartmouth on Monday. “I want to reassure you that we are working hard to find out as much information as possible in the days and weeks to come. We will be in this for months to come, I am sure.”

The perpetrator, who has been identified by police as 51-year-old Gabriel Wortman, was shot by police in a gas station parking lot in Enfield, outside Halifax, around noon on Sunday.

In the small community of Wentworth, which lost four residents to the violence, Lisa Owen and Darrol Thurier sat in front of their house on Monday, holding back emotion as they looked down the road toward where their neighbours’ house had been.

The couple who lived in the home, Sean McLeod and Alanna Jenkins, are missing, their cars torched and their house burned to its foundation.

‘Our hearts are broken:’ The victims of Nova Scotia’s mass shooting, Canada’s deadliest

Nova Scotia mass shooting: What we know so far about the victims, suspect and timeline of events

‘That innocent lives can be lost this way in our beautiful Canada is heart-wrenching.’ Readers mourn the lives lost in Nova Scotia mass shooting

Ms. Owen and Mr. Thurier found the body of another neighbour, Tom Bagley, in the driveway. They believe Mr. Bagley, a retired firefighter, was killed after seeing the fire and going to his neighbours’ place to help while out on his morning walk.

“It was the scaredest that I’ve ever been in my life …,” said Ms. Owen, who along with Mr. Thurier, is a military veteran. “There’s just no words.”

Another resident of the Wentworth area, Lillian Hyslop, was shot to death about 15 kilometres away, near the entrance to Wentworth Provincial Park.

The sites represent only two stops on the deadly rampage, which RCMP said Monday includes 16 separate crime scenes, including multiple burned houses and roadside murders.

The number of victims now significantly surpasses what was previously Canada’s worst mass shooting, the massacre at École Polytechnique that killed 14 women in 1989.

Multiple 911 calls began coming in from the beach community of Portapique, about 120 kilometres north of Halifax, at about 10 p.m. on Saturday. Officers arrived to find multiple casualties.

A tweet sent out by RCMP at 11:32 p.m. said police were responding to a firearm complaint in the area, where the gunman owned two properties and warned people to stay inside with their doors locked. Subsequent tweets between 8 and 9 a.m. on Sunday said the situation involved an active shooter, whom police identified as Mr. Wortman.

As the series of events becomes clear, questions are being raised about why RCMP chose not to use the province’s emergency alert system while chasing a subject they knew to be armed and extremely dangerous, but instead pushed the information out to the public through Twitter.

“We’ll be looking at that …,” said Chief Supt. Leather, when asked on Monday about the lack of an emergency alert. “We had relied on Twitter … because of the instantaneous manner that we can communicate. We’re aware that we have thousands of followers in Nova Scotia and we thought it was a way, a superior way, to communicate this ongoing threat.”

He had said the 14-hour manhunt was complicated by the fact the killer, who has been described as having an obsession with the RCMP, was masquerading as an officer and driving a detailed replica of a police car.

When the police vehicle could no longer be driven, Chief Supt. Leather says the gunman was able to obtain other vehicles and continue moving through the province “steps ahead of our investigators.”

In addition to Constable Stevenson, a 23-year veteran of the RCMP and a mother of two, other victims who have been identified include correctional services managers Alanna Jenkins and Sean McLeod; elementary school teacher Lisa McCully; Heather O’Brien, a nurse from Truro; and three members of the same family, Jolene Oliver, Emily Tuck and Aaron (Friar) Tuck.

Another RCMP officer who was shot has been released from hospital and is now recovering at home. That officer was identified by RCMP as Constable Chad Morrison, an 11-year member of the force.

Open this photo in gallery A memorial is set up across the street from the Debert School, where shooting victim Lisa McCully taught, in Debert, N.S., on April 20. JOHN MORRIS/Reuters

Chief Supt. Leather said some of the victims were known to the killer, but others appeared to have been randomly targeted. Chief Supt. Leather would not comment on any specific relationships, but said more detailed information is expected to be released later this week, including a timeline of events.

RCMP have not disclosed any known motivation for the attacks and say the gunman is not believed to have left a note.

Response to the tragedy has been complicated by the COVID-19 pandemic, which is affecting both the police investigation and the ability of communities to come together and grieve.

Still, around Nova Scotia on Monday, there were signs of a province in deep mourning. Memorials began appearing at the scenes of some shootings and at the RCMP’s provincial headquarters in Dartmouth. In Wentworth, the flag at the community’s only store – a combination gas bar, liquor store and food shop – flew at half mast.

In the wake of the attacks, Prime Minister Justin Trudeau said the government will fulfill its campaign promise to enact tougher gun-control measures, including banning military-style assault weapons. Without giving a precise timeline, he said the government would move as quickly as possible.

At a press conference on Monday afternoon, Public Safety Minister Bill Blair said some measures could be adopted through regulations, a quicker process than adopting new legislation. In addition to banning some types of firearms, he said the government is looking to strengthen gun-storage rules and adopt a “red flag law” to prevent some individuals from acquiring firearms.

RCMP Commissioner Brenda Lucki has said “various firearms” were used in the shootings, but no details have been released about the type of weapons that were used or whether the gunman was properly licensed to own them.

While RCMP say the killer was not “well known” to police, a neighbour described at least one interaction in the parking lot of the Dartmouth denture clinic in mid-February.

Bill McCormack, who has lived across the street from the gunman for about 20 years, says Mr. Wortman became angry about an unmarked Halifax Regional Police vehicle parked in his lot and that the situation escalated to the point that other marked police vehicles were called to the scene.

“He was shaking his arms, yelling, he was quite upset," Mr. McCormack said. "I thought, ‘All that over a parking lot?’”

In Dartmouth, the killer’s home and business sat cordoned off with yellow police tape on Monday, with a Halifax Regional Police car parked outside. A giant replica of a pair of dentures grinned pink and white from the side of the office building.

“You don’t know if a person has another side to them, or maybe they just go nuts or something," Mr. McCormack said. "But no normal person could do what he did. He’s not the person I know.”

Investigators are continuing to piece together one of Canada's deadliest mass killings. Officials say the alleged shooter, identified as 51-year-old Gabriel Wortman, was also killed after police intercepted him at a gas station in Enfield, N.S. Residents in the small community of Portapique, N.S., say they knew Wortman. The Canadian Press

Our Morning Update and Evening Update newsletters are written by Globe editors, giving you a concise summary of the day’s most important headlines. Sign up today.