Despite possible evidence of hundreds of graves at former schools for Indigenous children, challenges in making a clear conclusion have given rise to skeptics.

The Kamloopa Powwow in Tk’emlups te Secwepemc, British Columbia. An announcement in 2021 that the possible remains of 215 students in unmarked graves had been found at the former Kamloops residential school set off national shock waves.

New York Times: Published Sept. 20, 2024 Updated Sept. 21, 2024

The revelation convulsed all of Canada.

Ground-penetrating radar had found possible signs of 215 unmarked graves at a former residential school in British Columbia run by the Catholic Church that the government had once used to assimilate Indigenous children forcibly taken from their families.

It was the first of some 80 former schools where indications of possible unmarked graves were discovered, and it produced a wave of sorrow and shock in a country that has long struggled with the legacy of its treatment of Indigenous people. Prime Minister Justin Trudeau ordered flags to fly at half-staff, as many Canadians wore orange T-shirts with the slogan “Every Child Matters.”

Three years later, though, no remains have been exhumed and identified.

Many communities are struggling with a difficult choice: Should the sites be left undisturbed and transformed into memorial grounds, or should exhumations be done to identify any victims and return their remains to their communities?

While there is a broad consensus in Canada that children were taken from their families and died in these schools, as the discussions and searches have dragged on, a small universe of conservative Catholic and right-wing activists have become increasingly vocal in questioning the existence of unmarked graves. They are also skeptical of the entire national reconsideration of how Canada treated Indigenous people.

Three years after the announcement about the former Kamloops residential school site, they ask, why has no proof of any remains been uncovered anywhere in the country?

“There’s, so far, no evidence of any remains of children buried around residential schools,” Tom Flanagan, professor emeritus of political science at the University of Calgary and an author of “Grave Error: How the Media Misled Us (and the Truth About Residential Schools),” said in an interview.

“Nobody disputes,” he added, “that children died and that the conditions were sometimes chaotic. But that’s quite different from clandestine burials.”

The arguments by Mr. Flanagan and other skeptics have been roundly denounced by elected officials across the political spectrum who say evidence clearly suggests that there are many sites of unmarked burials.

Chief Rosanne Casimir of the Tk’emlups te Secwepemc Nation, who made the announcement about the Kamloops site, said: “The denialists, they’re hurtful. They are basically saying that didn’t happen.”

Security guards protecting the potential gravesites in her community have turned away people who have turned up late at night with shovels, she said.

Chief Casimir recalled holding the piece of paper in her hands about the potential gravesites that she read from to deliver the news and knew it would reverberate.

“I was thinking to myself, ‘This is horrible,’” she said.

Now her community is moving slowly and deliberately before deciding what to do next.

“We’ve had many conversations about whether to exhume or not to exhume,” Chief Casimir said. “It is very difficult and it is definitely very complex. We know that it’ll take time. And we also know that we have many steps yet to go.”

“We have to know for sure,” she added, “that we did everything that we can to determine: yes or no, anomaly or grave?”

The Canadian government and Pope Francis have apologized for the gruesome treatment of Indigenous people and the residential schools where children suffered so much abuse.

But the work to try to establish a precise number of potential graves will probably be difficult.

Murray Sinclair, a former judge who headed the National Truth and Reconciliation Commission to investigate the residential schools system, estimates that at least 10,000 students never made it home from the schools, which were established by the government and operated from the 1880s to the 1990s.

During that period the Canadian government forcibly removed at least 150,000 Indigenous children from their communities and sent them to residential schools, most of which were run by the Roman Catholic Church. Indigenous languages and cultural practices were forbidden, sometimes using force.

And when the children died the government refused to pay to return their bodies to the communities where they came from.

In Ontario, a search of records by investigators working for the province’s chief coroner has so far identified 456 students who died while attending 12 residential schools. Some records show where remains may be buried, the coroner said, but there’s uncertainty about those findings.

At the Kamloops school site, where one of the largest number of potential gravesites was reported, Chief Casimir said her tribe was still analyzing the results of its ground and document searches before deciding whether to conduct exhumations.

Doing so, she added, would be “very intrusive.”

Kimberly Murray, a lawyer and a member of a Mohawk First Nation, was appointed by the federal government in 2021 to examine the issues surrounding potential Indigenous graves and make recommendations about protecting and commemorating the sites.

She says she reminds communities that the work they are doing is because “the government purposely disappeared” Indigenous children, “by not proper record keeping, by not telling the families, by refusing to send them home.”

Many communities, Ms. Murray said, have expanded their physical searches and have employed additional methods to find remains.

One involves placing probes into the ground to detect specific soil acidity that is created by buried human remains.

Another process involves using short pulses of laser light to scan the surfaces of areas where government and church records, as well as the memories of former students, suggest there were burials. The process, using a technology known as lidar, can reveal patterns consistent with burial sites.

Some Indigenous communities have also brought in dogs trained to find remains.

In some cases, Ms. Murray said there was evidence that schools resorted to burying students in mass graves because of disease sweeping through the institutions or to store bodies until the spring thaw made digging graves possible.

Still, Indigenous communities have faced obstacles finding graves, Ms. Murray said, as they struggle getting access to records about the children who died at the schools from the Canadian government and the Catholic Church, despite pledges of cooperation.

Even if exhumations uncover remains, identifying individual bodies or determining a cause of death will probably be impossible, said Dr. Rebekah Jacques, a forensic pathologist who has been working with Indigenous communities that have potential gravesites.

Dr. Jacques has met members of Indigenous communities while serving as a member of a national committee on potential graves at school sites, and she said the question of exhumations hangs heavy over many groups.

“I don’t always have consensus myself about what to do,” she said. “So for me to expect for our communities to have consensus — well, I can really relate to that.”

She also believes that nothing Indigenous communities do, including exhumations, will satisfy skeptics.

For Mr. Flanagan and others who share his viewpoint, their disbelief that there are many gravesites is part of a broader argument against the key conclusion of a Truth and Reconciliation Commission: that the residential schools were a system of brutality that led to “cultural genocide.’’

“The narrative that’s been constructed pulls out all the bad stories and retails those and minimizes the benefit of residential schools,” Mr. Flanagan said, adding that converting Indigenous people in nations colonized by Europeans to Christianity and eradicating their cultures was once common worldwide.

“The churches believed that it was their religious duty, and the politicians thought that it helped to civilize the Indians,” He said. “Would we do that today? No. But our understanding wasn’t available to these people of 150 years ago.”

Government officials and experts say such views are driven by bias and a lack of understanding and sensitivity over what Indigenous children endured for over a century, until 1996.

“There is simply no question about the horrific impact that the residential schools policy had on Indigenous peoples,” said David Lametti, who was Canada’s justice minister and attorney general when Chief Casimir announced the findings at the Kamloops school site.

Government officials, he added, have little doubt that many of the radar anomalies found on school grounds will prove to be gravesites.

“Will every one of those anomalies turn out to be an unmarked grave? Obviously not,” Mr. Lametti, a former law professor now practicing law in Montreal, said. “But there’s enough preponderant evidence already that is compelling.”

Many Indigenous people who favor exhumations want their communities to move more quickly to find remains.

On his ranch in the Tk’emlups te Secwepemc Nation, Garry Gottfriedson, a poet, retired academic and rodeo rider, said that as a former residential school student he wants more openness and progress from leaders.

“It can drag on and on and on and in the meantime, it dies out,” Mr. Gottfriedson said of the discussion about what to do about the gravesites.

“I’m saying: Something needs to happen, let it happen,” he added. “But right now, it seems like nothing’s happening.”

Vjosa Isai contributed research.

Ian Austen reports on Canada for The Times based in Ottawa. He covers politics, culture and the people of Canada and has reported on the country for two decades. He can be reached at austen@nytimes.com. More about Ian Austen

A version of this article appears in print on Sept. 21, 2024, Section A, Page 1 of the New York edition with the headline: Sorrow Over Indigenous Graves In Canada, Joined by Skepticism. Order Reprints | Today’s Paper | Subscribe