TORONTO — Charges against a Canadian Aboriginal chief were dropped Wednesday at a hearing that followed the release of police dashcam video that showed an officer tackling and punching him.

Alberta Justice spokeswoman Carla Jones said in a statement the prosecution reassessed the available evidence and withdrew the charges of resisting arrest and assaulting a peace officer against Chief Allan Adam of the Athabasca Chipewyan First Nation.

The action came at a provincial court hearing in Fort McMurray, Alberta.,

Royal Canadian Mounted Police dashcam footage showing Adam's arrest, made public as part of a defense application to drop the charges, caused widespread public outrage and Prime Minister Justin Trudeau called it "shocking."

The 12-minute video shows an officer charging at Adam with his arm and elbow up and tackling him to the ground. It also shows the officer punching him in the head.

"My wife and I know we didn't do anything wrong," Adam said. "It was just for an expired license plate. I don't know the reason why it had to escalate."

Photos show Adam was left bloodied, with his face swollen. Alberta's police watchdog agency is investigating and Trudeau said the independent investigation must be transparent.

"If I ask them to be charged or fired, what would that accomplish?" Adam said, saying he wants to see broader reforms: "Make changes that are necessary."

Adam in the past has spoken out about excessive force and racism. He has noted that although aboriginal people represent 5% of Canada's population, they make up to 30% of the prison population.