A northwestern Ontario provincial police officer is facing a charge following an investigation into the death of a 42-year-old woman by the province's police watchdog.

The Special Investigations Unit says Gloria Assin was killed as officers were transporting her to the Kenora, Ont., detachment early on Sept. 23.

Assin died in a collision between the marked cruiser and a tractor trailer at Highway 17A and Redditt Road. She had been picked up for public intoxication and was sitting  — unbelted — in the back of a cruiser. She died of massive head injuries when the cruiser was rear-ended.

SIU director Ian Scott said Const. Troy Bender is facing one charge of dangerous driving causing death, and is to appear in court in Kenora on Dec. 20.

The SIU is an arm's length agency that investigates reports involving police where there has been death, serious injury or allegations of sexual assault.

With files from CBC Thunder Bay