HALIFAX -- An RCMP constable's final -- and fatal -- decision removed a killer's most potent advantage, likely saving many lives, the president of the National Police Federation said Saturday.

"She was a hero," said Brian Sauve, head of the union representing 20,000 RCMP members across Canada.

Const. Heidi Stevenson, 48, was killed last Sunday in a confrontation with a man driving a mock police car and wearing an RCMP uniform while carrying out a murderous rampage that left 22 victims dead.

According to a timeline released by the force Friday, 51-year-old Gabriel Wortman had already killed a number of people and burned homes in several communities by the time Const. Chad Morrison saw the shooter's car -- believing it to actually be Const. Stevenson because they had agreed to meet.

The gunman pulled up beside Morrison and immediately opened fire, wounding the officer, who managed to drive away to a local hospital. He notified other officers and dispatch that he was shot and that he was en route for emergency medical attention.

Stevenson then encountered the suspect, and their vehicles collided head on.

"She realized it was the bad guy, and she rammed him, from my understanding," Sauve said.

"I recognize she did something that probably saved countless lives. I don't know, five, 10, 20, how far this guy was going to go," he said.

After the collision, Stevenson's vehicle and the killer's replica vehicle were burning, and the shooter was no longer able to take advantage of the patrol car that RCMP officials have said was virtually identical to an authentic vehicle.

According to her obituary in The Chronicle Herald, Stevenson leaves behind her husband Dean and children Connor and Ava. She was described as a caring wife and mother, and a dedicated police officer with a strong work ethic.

The notice said Stevenson was determined to join the RCMP after graduating from Acadia University in 1993.

She took on a number of roles with the force, including community policing, communications, drug recognition expert and representing the RCMP as part of the Musical Ride.

Off the job, the notice said, Stevenson "was the busy parent who volunteered at the school. She was the friend who delivered cinnamon buns and homemade bread. She was the second mom to many kids who came over to play. She was the gentle smile when you needed it most."

Stevenson's move to take her killer's car out of commission was crucial.

Police have said that some of the murders occurred because the gunman had used the vehicle -- which was equipped with a replica light bar -- to pull over victims before he shot them.

On Friday, Supt. Darren Campbell spoke about the impact of Wortman having the replica police cruiser.

"I don't think it's difficult for non-police personnel or the public to understand that it would obviously complicate things," he said.

"You know, I've been a police officer for almost 30 years now and I can't imagine any more horrific set of circumstances, than when you're trying to search for someone that looks like you and the dangers that that causes, the complications that that causes."

The shooter managed to get out of his car, kill Stevenson and take her sidearm.

A passerby, Joey Webber, stopped and was fatally shot by the gunman. Webber had gone on a family errand toward Shubenacadie, N.S. The gunman would later be killed by police in Enfield, N.S.

Hundreds of vehicles, including dirt bikes, hot rods and trucks, with many flying Nova Scotia flags, paid respect Saturday to Webber. Friends and relatives lined a rural road in tiny Wyses Corner, N.S., to say goodbye.

The 36-year-old father of three was described in his obituary as a family man, a gifted horseman and a "true country boy."

Because of COVID-19, Webber's family was not able to have a proper funeral, so supporters staged the hour-long slow-moving procession.

Webber was a stock-car enthusiast. Many vehicles had his race car number 75 taped on the front and side. "Rest in Peace Joey," said the sign on one truck.

The first car in the procession, which passed Webber's house, was a pace car from Scotia Speedworld, where Webber once raced. There was also a pickup flying an enormous black-and-white checkered flag.

A vintage Oldsmobile 442 muscle car did a prolonged burnout -- the car sits in one spot while the rear wheels spin and smoke -- that drew applause from the crowd.

"That is what he liked," one woman said. "Right on, buddy."

A private family service for Stevenson will be held in the days to come. Stevenson would normally receive a regimental funeral, but COVID-19 makes that impossible.

The National Police Federation helped organize "Wear Red Friday" in part to remember her sacrifice in the line of duty, as well as the other loss of life.

Part of the purpose was for RCMP members to have a chance "to say a little prayer for Heidi and her family," said Sauve.

Police in Sudbury, Ont., saluted Stevenson as bagpipes wailed in the public square at a tribute attended by 10 people -- the maximum size permitted for a funeral.

Meanwhile, families of the victims continue to make arrangements to lay their loved ones to rest.

Obituaries posted in the Chronicle Herald say close friends and relatives are holding private funeral services for many of the victims.

Many families have asked for no visitors in keeping with the strict restrictions on social gatherings to prevent the spread of the novel coronavirus.

A planned guestbook signing for Gina Goulet, a 54-year-old denturist in Shubenacadie was cancelled to protect the health of her immediate circle, according to her obituary.

Some say public celebrations of the lives lost will be held after the COVID-19 pandemic is contained.

Until then, many families have asked people to pay their respects through online condolences or donations to personal crowdfunds or other causes.

Some have found workarounds that allow mourners to pay their respects within the constraints of physical distancing.

An obituary for Lisa McCully says the 49-year-old teacher and mother of two will be remembered at a private funeral service Sunday that will also be webcast.

This report by The Canadian Press was first published April 25, 2020.

-- With files from Michael Tutton and Andrew Vaughan in Halifax.