The 16-year-old resident of the Stoney Nakoda First Nation appeared in court briefly to face charges of attempted murder and several firearms violations.
The suspect, whose name cannot be published under Canadian juvenile law, was arrested on August 24, said Royal Canadian Mounted Police Corporal Curtis Peters.
"Officers also located the dark-colored car and the gun that were believed to be involved in the shooting," he said.
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The 60-year-old tourist, who was seriously wounded, was shot in the head on August 2 while driving with his family on a highway from Banff National Park, about 60 kilometers (37 miles) west of Calgary, Alberta.
Police suspected the bullet, which penetrated the suspect's skull, came from a sedan that passed the tourist's eastbound truck.
His wife and two others in their vehicle were also treated for minor injuries sustained in an ensuing crash.
Police had initially believed it was a case of road rage, but later said it was more likely that the man was targeted because he was mistaken for someone else.
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"We have no reason to believe that the victim and the accused were known to each other, or that they had any contact outside of the shooting," Peters said.
The victim, whose name has not been identified under Canada's strict privacy law, was flown home mid-August for further treatment of his brain injury and underwent surgery to remove the bullet.
Peters said the bullet is now on its way back to Canada for "forensic examination" to match it to the seized firearm.
A German consular official has said the victim has "severe and life-changing injuries," including speech loss and partial paralysis on one side.
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