HALIFAX -- The inquiry into the 2020 mass shooting in Nova Scotia released more details Monday about missteps the RCMP made as investigators tried to identify the killer's vehicle early in his 13-hour rampage.

The inquiry has heard that during a chaotic 40-minute span on the night of April 18, 2020, the perpetrator fatally shot 13 people and set fire to several homes in Portapique, N.S., before escaping the rural enclave at 10:45 p.m. as police closed in. The gunman would kill another nine people the next day before he was shot dead by RCMP officers at a gas station north of Halifax.

Early in the RCMP's investigation, several witnesses said they had spotted the killer driving a vehicle that looked like a fully marked RCMP cruiser. The inquiry has also heard that some of that key information did not get relayed to senior officers.

The descriptions given to 911 call-takers and police at the scene were accurate, but new evidence points to confusion and mistakes as the Mounties struggled to determine what vehicles the suspect owned and what he was actually driving.

For the first time, the inquiry revealed Monday that early on the first night, a senior Mountie was told the suspect owned several decommissioned police cars.

During a subsequent interview with inquiry investigators, RCMP Staff Sgt. Brian Rehill said operators at the Operational Communications Centre in Truro, N.S., had “personal knowledge” about the perpetrator.

“Some of them live out in that rural area,” said Rehill, who at the time was the centre's on-duty risk manager. “They said, 'That's the guy that collects those decommissioned cars.' So then everybody said, 'OK, we're looking for one of these white, Ford Tauruses.”'

But that key information was slightly at odds with what police were being told: the killer wasn't driving an old, unmarked police car but a fully marked cruiser.

At 10:32 p.m., as three officers were searching for the gunman on foot, Rehill told another senior Mountie: “They're saying someone in a police car is shooting people. But we don't think it's a police car. I think somebody is mixed up.”

Once the Mounties had confirmed that all of their patrol cars had been accounted for, the focus of the vehicle search turned to finding an old, unmarked police car, the inquiry has heard.

Previous evidence from the first three officers on the scene confirm they did not consider the possibility that the suspect could be driving what looked like a marked RCMP cruiser.

“At no point did I ever envision that it was an exact replica of the cars we drive,” Const. Aaron Patton told inquiry investigators.

On another front, an oversight early in the investigation led the Mounties to believe the killer owned only one Ford Taurus Interceptor.

At 12:35 a.m. on April 19, 2020, Operational Communications Centre supervisor Jen MacCallum asked a dispatcher to issue an advisory for police to be on the lookout for two vehicles associated with the suspect: a white 2015 Mercedes and a white Ford Taurus.

The inquiry's investigators later concluded the RCMP failed at that time to complete a database search for more vehicles registered to Berkshire Broman Corp., a New Brunswick company controlled by the suspect.

In all, the killer owned four decommissioned vehicles, all of them Ford Taurus Interceptors. Three of them were 2013 models. The fourth, a 2017 model modified to look exactly like an RCMP cruiser, was used by the killer during most of his time at large.

As the search for the killer continued through the first night, RCMP officers in Portapique found one Taurus at the killer's summer residence, which had been set on fire before he left the village.

Const. Patton told investigators he believed the car was the one they were looking for, and Rehill later suggested the suspect could have abandoned the car and fled in another vehicle.

At 1:08 a.m. on April 19, 2020, the RCMP issued an advisory to its officers to be on the lookout for 51-year-old Gabriel Wortman, an armed and dangerous active shooter associated with two vehicles: a C300 Mercedes and “an old police car (may be burned at scene).”

Less than an hour later, police in Halifax found a white Taurus behind Wortman's denture clinic in the Halifax area. They confirmed that it had not moved for some time because it was covered in snow.

By 4:35 a.m. senior RCMP officers conducted a briefing at their command post in Great Village, N.S. In notes provided to the commission, Staff Sgt. Steve Halliday - the operations officer in the district - stated that three of the gunman's Tauruses had been found: the snow-covered one and two torched vehicles in Portapique.

But inquiry investigators determined that was an error. In fact, transcripts of radio communications show senior Mounties didn't know about all three vehicles until 7:20 a.m., when an officer confirmed the plate number on the Taurus found at the shooter's home.

That's when senior officers were made aware of the other former police vehicles connected with the gunman's company. It was also around that time that the suspect's common-law spouse, Lisa Banfield, emerged from hiding near the couple's home in Portapique and told police how her husband had escaped in a fully marked vehicle loaded with weapons.

At 7:22 a.m., RCMP Staff Sgt. Bruce Briers - the risk manager who took over for Rehill - received word from Halifax Regional Police that Banfield's sister and her partner had handed over images of the killer's replica vehicle, which showed it had emergency lights and authentic decals.

According to notes provided to the inquiry, at 7:55 a.m. Staff Sgt. Halliday came to the conclusion that the gunman “could be on the run in a fully marked RCMP (vehicle).”

“This has to be communicated out to members all municipal agencies, (police departments) and border crossings and we have to get it out to the public ASAP,” his notes say.

At 9:32 a.m., police received a call from April Dares, a resident of West Wentworth, N.S., who reported hearing gunshots and seeing a police car leave the area.

Investigators would later learn that the car was the one they were looking for, but the public had yet to be alerted about the vehicle. The gunman killed three people on Hunter Road that morning before moving on to kill six others, including a pregnant woman and a Mountie.

The photograph of the suspect's vehicle was not shared with the public until 10:17 a.m., three hours after the photos were obtained by police.

-- With files from Michael Tutton in Halifax.