RCMP say at least 17 people are dead, including one of their officers, after a man who at one point wore a police uniform and drove a mock-up cruiser went on a rampage across northern Nova Scotia in one of the deadliest rampages in Canadian history.

Police said Sunday night the suspected shooter, 51-year-old Gabriel Wortman, was killed after being intercepted by officers in Enfield, N.S.

Const. Heidi Stevenson, a 23-year member of the force and mother of two, was identified as the officer killed. A male officer suffered non-life threatening injuries. Lisa McCully, a teacher at Debert Elementary, was also killed in the attack, according to a news release from the Nova Scotia Teachers Union.

"Our hearts are heavy with grief and sadness today as we have lost one of our own," said Brian Sauve, president of the union representing RCMP officers.

RCMP Commissioner Brenda Lucki told CBC News Sunday evening the death toll stood at 16, plus the shooter, which surpasses the 14 victims killed in the 1989 Polytechnique massacre in Montreal.

RCMP Chief Supt. Chris Leather earlier told an evening news conference that "in excess of 10 people" had been killed." Leather said it was hard to specify the exact number of victims, "because as we're standing here, the investigation continues into areas that we have not yet explored across the province."

RCMP Constable Heidi Stevenson, a mother of two and a 23-year veteran of the force, was killed during a gunman's rampage. Stevenson is seen in a 2015 photo posted to the Nova Scotia RCMP's Facebook page. (Nova Scotia RCMP/Twitter)

Leather said the killings appear to be, "at least in part, very random in nature."

The first reports of an active shooter came from Portapique, a community about 40 kilometres west of Truro, which residents described as a quiet place to live that attracts cottagers from Halifax in summer months.

Upon arrival, police found "several casualties" inside and outside a Portapique residence, Leather said, but they could not locate the suspect. He added there were "multiple sites in the area including structures that were on fire."

Lee Bergerman, commanding officer for the RCMP in Nova Scotia, said the day's events have left many families in mourning. "The impact of this incident will extend from one end of the province to the other," she said.

By late Sunday morning, the suspect was stopped about 90 kilometres away in Enfield, a scene that was surrounded by a half dozen police vehicles. Yellow police tape surrounded the gas pumps, and a large silver-coloured SUV was being investigated by police.

A body was seen lying at the gas station. Police would not comment on whether it was Wortman.

Police watchdog investigating death of gunman

The province's Serious Incident Response Team (SIRT) said Sunday evening it was investigating the shooting of a man in Enfield by RCMP officers.

According to a release, the suspect was involved in a serious criminal event in Shubenacadie, N.S., which is north of Enfield. A confrontation with police followed in Enfield, "resulting in officers discharging their firearms."

The police watchdog said it was contacted by RCMP and has assumed responsibility for the investigation of the suspect's shooting.

The organization is responsible for investigating all serious incidents involving police in Nova Scotia, whether or not there is an allegation of wrongdoing.

Motive turned to 'randomness'

Lucki said she believed the shooter had an initial "motivation" at the beginning that "turned to randomness."

"Our investigation will tell that. We don't know for sure, and we're going to have to do a lot of work on finding the motivation — a lot of background, a lot of profiling-type events and a lot of crime scene processing," she said.

(CBC News)

Through the morning Sunday, police updates about the active shooter investigation included warnings that Wortman was considered dangerous and may have been dressed as an RCMP officer in a lookalike RCMP vehicle.

"The fact that this individual had a uniform and a police car at his disposal certainly speaks to it not being a random act," Leather said.

Due to privacy reasons, Leather said he was not able to discuss Wortman's relationship with the victims, besides saying some of the victims did not appear to have a relationship with the gunman.

Bergerman said Sunday she met with Const. Stevenson's family. "There are no words to describe their pain," she told reporters.

RCMP are shown near a gas station in Enfield, N.S., shortly after the gunman's police chase came to an end around 11:40 a.m. local time. (Eric Woolliscroft/CBC)

"Heidi answered the call of duty and lost her life while protecting those she served."

"Two children have lost their mother. And a husband has lost his wife. Parents have lost their daughter and countless others lost an incredible friend and colleague."

Bergerman also said a second male officer was in hospital with non-life threatening injuries.

WATCH | Police announce veteran RCMP officer killed during gunman's rampage:

Const. Heidi Stevenson is survived by her husband and two children. Another officer was injured during the incident that occurred over the span of 12 hours across several communities. 1:05

'We heard gunshots'

Darcy Sack, a Shubenacadie, N.S., resident, said she and her friend came across two burning police vehicles and the silver suspect vehicle while out driving on Sunday morning near Highway 102, one of the province's main arteries.

"We were right behind the police car that was on fire. There was one officer we could see on scene and then all of a sudden, he went running toward one of the burning vehicles," Sack said. "We heard gunshots."

Sack said her heart was pounding the whole time.

Darcy Sack, a Shubenacadie, N.S., resident, said she and her friend came across two burning police vehicles and the silver suspect vehicle while out driving on Sunday morning near Highway 102 1:34

"I had that feeling that something was wrong with the [police officer's] partner — the way he looked. My heart went out to him," she said.

Sack said they then turned on to the highway and then saw the shooter in the silver car again being chased by police. She said he was dressed like a police officer.

Eyewitness saw homes burning

Mike MacKay, who lives just off the Glooscap Trail in Portapique said he saw police cars on the Portapique Beach Road around 11:30 p.m. Saturday, across the Portapique River from his home.

"We saw a fire down the road, and thought that's all that it was. Then we saw a second fire and a third fire," said MacKay in a phone interview from his home Sunday morning.

Lifelong Portapique resident Peter Hodge, 65, woke up at 1:30 a.m. and saw lights so bright, he thought it was a fire. He then realized that the bright lights were from "probably upwards of 14 police cars in the community."

Christine Mills, another resident, said it had been a frightening night for the community, which was suddenly filled with armed officers patrolling the streets. In the morning, helicopters flew overhead searching for the suspect.

She said she was fearful the shooter might have gone through the woods and attempted to enter her home.

"It's nerve-wracking because you don't know if somebody has lost their mind and is going to beat in your front door," she said.

WATCH | N.S. resident 'up all night' following active shooter incident:

CBC has learned RCMP and fire fighters were called to a property in Wentworth, N.S., on Sunday morning shortly before 10 a.m. to respond to a house fire.

Police have not released any information about whether it is connected to the shooter investigation.

The RCMP would not comment on the report of multiple house fires when asked by CBC News on Sunday morning.

'You're on edge'

MacKay said he did not sleep at all overnight Saturday.

"You're on edge. It's a small community," said MacKay. "It becomes quite a concern."

Coun. Tom Taggart, who represents the area for the Municipality of Colchester, described Portapique as a quiet community with many seniors.

Taggart said there are many seasonal homes in the area, which has around 100 residents but swells to 250 in the warmer months.

"It's a beautiful, quiet, rural community," said Taggart, adding that the situation is not something he'd expect to happen in "cottage country."

A person with the name Gabriel Wortman is listed as a denturist in the Halifax area on the Denturist Society of Nova Scotia website.

A person with the name Gabriel Wortman is listed as a denturist in the Halifax area on the Denturist Society of Nova Scotia website. He is listed as the owner of this property in Dartmouth, where police were Sunday afternoon. (Eric Woolliscroft/CBC)

According to property records, Wortman owned a denture clinic and two other properties in Dartmouth and three properties in Portapique.

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