The gunman evaded police by driving in a car identical to a Mountie cruiser.

A violent domestic assault could have triggered a murderous rampage in Nova Scotia that left 22 victims dead, 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 in Halifax, adding that the killer, 51-year-old Gabriel Wortman, had been in a long-term relationship with the woman.

Campbell confirmed she escaped from the couple’s home in Portapique on Saturday night and hid overnight in the woods as the killer began shooting neighbours and setting fire to homes. Sources say the woman had been beaten and allegedly bound in some way.

“It was a significant incident,” Campbell said of the assault.

After the woman 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.

Police also learned the suspect “was in possession of several firearms that included pistols and long-barrelled weapons,” he said.

But he also disclosed that a gunshot victim encountered as police arrived Saturday night said he was shot from a vehicle that resembled a police car. The victim survived. During the night, police learned the suspect owned “several vehicles that looked like police vehicles,” Campbell added.

Police responding to the initial calls in Portapique found “several people who were deceased, some of which were lying in the roadway.” Several buildings were “already fully engulfed in flames,” including the suspect’s home and garage, which burned to the ground, Campbell said.

Police confirmed Wednesday that the suspect managed to escape from a perimeter they had set up around the rural area, but they didn’t realize he was gone until some time between 7 a.m. and 8 a.m. on Sunday when his girlfriend – whom they have described as a “key witness” – revealed details about the fake police car and authentic police uniform.

In all, 13 people were killed in the Portapique area.

Later that morning, police started received a series of 911 calls from Hunter Road in the Glenholme area, about 60 kilometres from Portapique.

That’s where Wortman killed two men and one woman before setting a home on fire. Two of the victims were known to the gunman, Campbell said.

The assailant then approached another residence in the Glenholme area, where he knocked on the door. But the people inside did not answer and he left. The occupants called 911 and confirmed the suspect was armed with a long-gun and was driving what looked like a police car.

In the Wentworth area, the suspect shot a woman walking on the roadside around 9:30 a.m.

In nearby Debert, N.S., just after 10 a.m., he pulled over a vehicle and shot the driver – and he did the same a little further down the road.

As police continued their search, RCMP Const. Chad Morrison had made arrangements to meet Const. Heidi Stevenson at Highway 2 and Highway 224, which is south of Shubenacadie, N.S.

Morrison soon spotted what appeared to be another RCMP cruiser coming toward him, which he assumed was Stevenson’s vehicle, Campbell said.

As Wortman pulled alongside Morrison’s vehicle, he opened fire, wounding the officer. “Const. Morrison received several gunshot wounds,” Campbell said.

As Morrison retreated from the scene in his vehicle, he alerted the dispatcher that he had been shot and was heading to an Emergency Health Services station for treatment. (Morrison survived and has since returned home.)

Campbell said the shooter soon spotted Stevenson’s vehicle heading northbound on Highway 2 as he was driving in the opposite direction.

The senior Mountie said Wortman rammed her car head-on.

“Const. Stevenson engaged the gunman,” Campbell said. “The gunman took Const. Stevenson’s life and he also took her sidearm and her magazine.”

When a passerby stopped nearby, the gunman opened fire again, killing that individual. He then took that person’s vehicle, a silver SUV, and again headed south on Highway 224.

Campbell said the killer then stopped at a nearby home on the highway, where he fatally shot a woman he knew.

He then removed his police uniform, loaded his weapons into the woman’s red Mazda 3 and drove south to the Irving Big Stop gas station in Enfield, about 90 kilometres south of Portapique.

That’s where he was spotted by an RCMP officer.

“There as an encounter, and the gunman was shot and killed by police at 11:26 in the morning,” Campbell said.

John Hudson, who had known Wortman for about 18 years, said he was sometimes openly controlling and jealous of his long-time girlfriend.

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

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.”‘

Hudson said his neighbour had been purchasing used police vehicles at auctions.

“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.”

He said the information the girlfriend provided to police was crucial to stopping the gunman.

“If it wasn’t for (her) giving that information, it would have been a lot worse,” said Hudson. “They wouldn’t have known to be looking for an RCMP car.”

Police said the gunman acted alone during his violent rampage, but investigators said they are trying to determine whether anyone assisted him before the shooting began.