MONTREAL — To many, the deaths seemed strange from the start. Seven indigenous students were found dead between 2000 and 2011 in Thunder Bay, a remote Ontario town on the shores of Lake Superior, near the Minnesota border. Five of the bodies were found in local rivers.

Other deaths followed: A 41-year-old man found in a river in 2015; the drowning deaths of a 17-year-old girl and a 14-year-old boy in the same month in 2016; and many more. In all, dozens of indigenous people have died in the area over the past two decades under mysterious circumstances.

Thunder Bay police had ruled many of these deaths not to be suspicious, closing some of the cases before an autopsy had been conducted. But a report released Wednesday came to a blunt and distinctly different conclusion, harshly questioning the credibility of the police force and calling for nine cases to be reopened.

The two-year investigation by the Office of the Independent Police Review Director — an independent watchdog agency — included a review of 37 cases. The report slammed Thunder Bay police for inept investigations and systemic racism in handling the cases of indigenous victims. The report made 44 recommendations, including that Thunder Bay’s police force be reviewed by outside law enforcement officers for the next three years. The police department hasn’t responded to the individual recommendations yet but accepted the report as a whole.

On Friday, as a result of a separate probe, the Thunder Bay police services board was disbanded and an administrator was appointed to oversee the force.

The rebuke, while welcome to local indigenous people, also left many grappling again with the magnitude of the problem.

“It’s a lot of mixed feelings,” said Jana-Rae Yerxa, who works with young indigenous students in her position at a local college and who grew up in an Anishinaabe nation about three hours away. “Either way,” she said, whether their concerns were rejected or validated, “it was going to be hard news for the indigenous community.”

Although relatively isolated, Thunder Bay serves as a hub for an expanse of northern land scattered with Anishinaabe communities with no road access. Residents, especially young people, fly to Thunder Bay for schooling or other services.

In many of the cases reviewed, basic policing protocols hadn’t been followed, the report concluded. Officers sometimes attributed deaths to hypothermia, drowning or suicide while ignoring fresh injuries to the victims’ bodies. In some cases, they dismissed the fact that female victims were found with their pants pulled down.

At the same time, there were consistently troubling reports of other violence against indigenous residents. In 2016, a Thunder Bay restaurateur was approached by an indigenous man “soaking wet and bleeding from the head,” the report noted. “The man told her that two white men got out of a blue truck, beat him up and threw him in the river. He got out of the river but the men threw him back in.”

The restaurateur recalled that police said it was a “chosen lifestyle” for the man to be near the river.

A teenager reported the next year that two white men had tried to force him into a pickup truck.

“Early assumptions . . . were made that because an indigenous person was found in the river that they just drowned, or that they were just intoxicated,” said Gerry McNeilly, who was responsible for the report as head of the Office of the Independent Police Review Director. His office receives and follows up on complaints from the public about police forces in Ontario.

“It’s wrong to make assumptions before you’ve fully gotten all the evidence,” McNeilly said, adding that he found “complete discrimination” in how police treated indigenous victims.

The report’s authors acknowledged that the passage of time may make it impossible to solve some cases.

“The point of recommending re-investigation is to reflect that in these cases, the original investigations were so incomplete or inadequate to prevent the ruling out of foul play or third-party contributions to the deaths,” they wrote.

Julian Falconer, a lawyer who has represented some of the Anishinaabe nations and the family of one of the deceased, said he welcomed the report’s frankness. For many years, he said, people like him have been reluctant to voice their concerns because they were so disturbing.

“It is quite clear that some of these deaths arose by human intervention — that there is an activity in Thunder Bay that is considered entertaining, by some, to go down to the river and throw ‘Indians’ in the water,” Falconer said. “It just seemed too fantastical. But now, years later, case after case, it’s not so fantastic anymore. It’s exceedingly sad.”

He said he welcomed the report’s 44 recommendations, including that sudden-death and murder investigations in Thunder Bay be peer-reviewed by officers from outside the city for the next three years.

“To get change, you need help from the outside,” he said. “This was the journey of the Deep South in the U.S. in the ’60s. I don’t see this as any different.”

The top chief of a regional coalition of Anishinaabe nations also welcomed the board’s findings and insisted there must be tough repercussions if the police department doesn’t change its ways.

“At the end of the three years . . . if they’re not compliant, we would strongly recommend that the police service be disbanded,” Grand Chief Alvin Fiddler said.

In a statement on Wednesday, Thunder Bay police accepted the report, saying it was formally acknowledging that it “must address the systemic racism, barriers and biases that exist within its service.” It said it would carefully review the recommendations.

The cases aren’t all in the past. On Dec. 9, the body of 17-year-old Braiden Jacob was discovered on a local golf course. Jacob had reportedly traveled from the tiny Webequie First Nation to Thunder Bay for grief counseling.

Thursday evening, the day after the report’s release, police announced they were treating the youth’s death as a homicide. By Friday, they had charged 22-year-old Jonathan Yellowhead with second-degree murder in the case.

Correction: An earlier version of this story said that law enforcement in Thunder Bay agreed to be reviewed for three years. In fact, the Thunder Bay police department hasn’t responded to the individual recommendations yet but accepted the report as a whole. This article has been updated.