Police said they have labelled the case a murder-suicide.
The Alberta Serious Incident Response Team, known as ASIRT, said in a release Friday that investigators found evidence a woman was taken against her will from a home in Medicine Hat on Nov. 22.
At the time, police said a woman in distress had called 911. When officers arrived at the house, no one was home but there were signs of a struggle.
"Police located a motor vehicle believed to be associated with the abduction and attempted to stop it," said the ASIRT release said. "However, the vehicle fled."
City police followed the vehicle and, as the chase continued west outside the community, RCMP got involved.
Police earlier said that during the police chase, the vehicle's passenger opened and closed, and officers believed the woman was in "imminent danger."
ASIRT said the vehicle was travelling up to 177 km/h before it turned onto a secondary highway, then suddenly veered into the path of a semi truck.
Branden Anderson, 27, and his passenger 33-year-old Crystal Trotchie, were killed.
The truck driver received minor injuries.
Friends on social media said Anderson and Trotchie were married but had recently separated. They had two children.
Chief Andy MacGrogan with the Medicine Hat police said officers are continuing to investigate the case as a murder-suicide.
"We're just basically finishing off some of the loose ends."
ASIRT executive director Clif Purvis said officers were not at fault.
"I am satisfied that none of the members involved from the RCMP or from the Medicine Hat Police Service caused the death of these two individuals," he said.
"I'm satisfied they did not cause the collision that caused the death."
— With files from CJCY
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