Two RCMP officers observe a moment of silence to honour slain Const. Heidi Stevenson and the other 21 victims of the mass killings at a checkpoint on Portapique Road in Portapique, N.S. on Friday, April 24, 2020. At least 22 people are dead after a man, who at one point wore a police uniform and drove a mock-up cruiser, went on a murder rampage in Portapique and several other Nova Scotia communities.

Image Credit: THE CANADIAN PRESS/Andrew Vaughan

HALIFAX - A murderous rampage in Nova Scotia that left 22 victims dead could have been triggered by a violent domestic assault, the RCMP confirmed during a news conference Friday that provided grim details of killings that spanned 90 kilometres.

"That could have been a catalyst," RCMP Supt. Darren Campbell said of Gabriel Wortman's attack Saturday night on a woman with whom he was in a long-term relationship.

Campbell said the woman escaped from the couple's home in Portapique, N.S., and hid overnight in the woods as the 51-year-old Wortman began shooting neighbours and setting fire to homes. Sources say the woman had been beaten and bound in some way.

"It was a significant incident," Campbell said of the assault, which was followed by 22 murders in five communities in what police called three distinct "clusters" of violence.

One acquaintance said Wortman had been in domestic conflicts in the past. John Hudson, who had known Wortman for about 18 years, said he was sometimes openly controlling and jealous of his longtime girlfriend.

"I didn't see him hitting her or anything like that," Hudson said in an interview. "But I know they fought."

READ MORE: RCMP offer details about timeline for mass killing in Nova Scotia

RCMP officers prepare to take a person into custody at a gas station in Enfield, N.S. on Sunday April 19, 2020. The Nova Scotia RCMP provided a partial timeline of what happened last weekend when a man posing as an RCMP officer killed 22 people before he was fatally shot by police on Sunday, a little over 12 hours after he started what would become one of the worst mass killings in Canadian history.

Image Credit: THE CANADIAN PRESS/Tim Krochak

Hudson recalled a bonfire party about 10 years ago when an argument between the two left the woman locked out of their home in Portapique.

"I was with her, trying to get her stuff out of there," Hudson said. "People had been drinking ... and it was a crazy night ... and he didn't want her to leave — but he wouldn't let her in the house."

Hudson said at one point, Wortman removed the tires from the woman's vehicle and threw them into the ditch to prevent her from leaving.

"So, I went to get (her clothes) and what he said to me was: 'I don't want anyone in my house. If you come in my house, I'm just telling you, I've got guns in here.'"

While police say the assault may have been the spark for the rampage, Campbell also described a chain of events that helped the suspect expand his violence and arson into three "clusters" of attacks in five communities for over 12 hours.

One key element was his use of a carefully prepared replica police vehicle, which police revealed Friday was one of four Ford Taurus vehicles he'd owned.

The car he was driving wasn't licensed, and police say they didn't know of its existence initially as they entered Portapique to find dead and injured citizens in the coastal town.

"I can't imagine any more horrific a set of circumstances than trying to search for someone that looks like you," said the officer of the suspect.

After Wortman's girlfriend emerged from hiding at daybreak on Sunday, she called 911 and informed investigators that Wortman "was in possession of a fully marked and equipped replica RCMP vehicle and was wearing an RCMP uniform," Campbell said.

That came in addition to an earlier witness — wounded by a gunshot blast as Wortman drove by — telling investigators he'd been shot by someone driving a vehicle that resembled a police car.

In addition, police soon learned the suspect "was in possession of several firearms that included pistols and long-barrelled weapons," Campbell said.

Some of the guns were obtained in the United States and one in Canada, according to Campbell. Police have already said that Wortman wasn't licensed to own the weapons.

There are key questions remaining for investigators, prime among them whether there was any element of pre-meditation once the killing and arson began.

Attacks in the Wentworth and Shubenacadie areas on Sunday morning included a number against people who knew the gunman. "It's maybe very likely they were people he might have had an issue with," Campbell said.

Investigators have made progress tracking down how Wortman obtained the decals for his fake police car and the light bar on its roof but are still working on the issue of whether wrongdoing was involved, he added.

Hudson said Wortman had been purchasing used police vehicles at auctions for years. "He picked the best one and brought it up here, had it in his garage and (added) decals to look just right," Hudson said.

"He was very meticulous on everything he did ... He also trained himself on electronics, so he'd know how to hook up the lighting and everything like that for the car."

The carnage and chaos Saturday night in Portapique, where 13 people died, made tracking the fleeing man challenging.

When officers arrived at the scene there were dead bodies already lying in the roadway, and buildings were fully engulfed in flames, including the suspect's garage and home — which burned to the ground.

The fire at Wortman's home damaged or eliminated key evidence, such as where his police clothing and weapons came from, Campbell said.

Police disclosed new details about the death of one RCMP officer and the injury of another near Shubenacadie, illustrating the role the killer's replica vehicle played.

Campbell said Const. Chad Morrison and Const. Heidi Stevenson had agreed to meet, and when a police cruiser approached, Morrison assumed it was his colleague. Instead it was Wortman, who opened fire, wounding the officer, who managed to drive away to a local hospital.

Stevenson then encountered the suspect, and their vehicles collided head on, but the gunman managed to get out, kill the officer and take her sidearm.

He then carried on to murder one civilian and take his SUV, and then committed a final murder, changing cars again and clothing.

Police who encountered him at the Irving Big Stop gas station in Enfield, about 90 kilometres south of Portapique, shot Wortman dead next to a gas pump at 11:26 a.m. on Sunday.

This report by The Canadian Press was first published April 24, 2020.

News from © The Canadian Press, 2020