The Nova Scotia gunman used his replica police cruiser to flag down motorists before murdering them, and also targeted passersby who offered to help and a lone walker out for a Sunday morning stroll. Gabriel Wortman – who killed 22 people on Saturday and Sunday – also stole weapons from a police officer he murdered, switched vehicles and changed clothes to elude capture during his 12-hour killing spree. The grim details emerged on Friday as police released their first detailed timeline of Canada’s worst mass shooting. “I’ve been a police officer for almost 30 years now and I can’t imagine a more horrific set of circumstances, when you’re trying to search for someone that looks like you,” Royal Canadian Mounted Police (RCMP) Supt Darren Campbell told reporters. “Obviously that was an advantage the suspect had on the police, on the public – and on every person he encountered through the course of his rampage.” Police said that before the shooting, Wortman beat and handcuffed his longtime girlfriend in a “significant assault”. Campbell said that an argument between the two might have been “the catalyst of events” over the weekend. The first victim found by police on Saturday night was a driver with a gunshot wound in the rural town of Portapique, set in thick forest. Fanning out across the crime scene, officers found several buildings on fire – and 13 other victims. Authorities soon realized the suspected gunman owned several decommissioned police cruisers, but officers initially mistakenly believed all were accounted for. Two were found on fire at his house, and officers in Halifax located the third at another one of Wortman’s properties. “We weren’t aware at that particular time and came, and became known to us later that he had a fourth vehicle,” said Campbell. “And that was the vehicle that he was using during his rampage.” It wasn’t until Wortman’s girlfriend escaped into the woods and contacted police, that they learned of the fourth vehicle. The police response was also hobbled by a mistaken belief that a single country road was the only way in and out of the first crime scene. It was not until a second wave of emergency calls on Sunday morning that officers learned that the suspect had escaped and was more than 60km away, Campbell said. “Our investigation has revealed that the gunman attended a residence on Hunter Road in the Glenholme area. At that location, the gunman killed two men and one woman and he set the residence on fire,” he said. “At least two of the victims were known to the gunman.” Wortman then went to another house, whose residents he knew. But as they saw him dressed as a police officer and brandishing weapons, they refused to answer the door, instead calling 911. Wortman then continued down the highway, at this point using his replica police vehicle to pull over drivers. “Witnesses described that the suspect had pulled over one of the vehicles and then shot one of the drivers,” Campbell. “He continued driving down that same highway and he encountered his second vehicle and he shot and killed that victim.” Police also gave the first detailed account of the death of constable Heidi Stevenson, a 23-year veteran of the RCMP. Stevenson and a colleague, constable Chad Morrison, both hunting for Wortman, had agreed to meet at a highway intersection. When a white vehicle with police markings approached, Morrison thought it was Stevenson. “The approaching police vehicle was actually driven by the gunman, said Campbell. “The gunman pulled up beside constable Morrison and immediately opened fire,” wounding Morrison. Morrison sped off, but Wortman then collided with Stevenson as she arrived at the scene in her cruiser. He shot her dead and stole her weapon and ammunition, before killing a passerby in a silver SUV. Wortman then set Stevenson’s patrol car and his own replica cruiser on fire, stealing the SUV from his latest victim. He drove a short distance to the house of a woman he knew, fatally shooting her. He then changed out of his police uniform, placed his weapons in her vehicle, and went towards a nearby gas station in the town of Enfield. Officers filling up an unmarked vehicle saw Wortman and drew their weapons. “There was an encounter and the gunman was shot and killed by police at 11.26 in the morning,” said Campbell. Police are still investigating how Wortman was able to obtain a number of firearms – a mix of pistols and long-barrelled guns. Only one of weapons has been traced back to Canada. The rest are believed to have originated in the United States.