Sentencing began Thursday for an Alberta man who dressed up as a police officer before he kidnapped and sexually assaulted a teenager last year.

A psychologist specializing in forensics took the stand in a Red Deer courtroom to testify whether Gerard Baumgarte poses a high risk to reoffend.

Baumgarte, who is 57, pleaded guilty last fall to six charges in relation to the abduction in February 2009, including impersonating a police officer and assault with a weapon.

Court heard he was dressed as a constable and was driving a car equipped with flashing lights when he picked up a 16-year-old girl on her way home from a convenience store.

He sexually assaulted her over a span of 46 hours before dropping her off at a Red Deer shopping mall.

Sentencing arguments were expected to last two days.

Court heard last year that Baumgarte had fantasized about kidnapping someone. As well, he had always wanted to be a police officer, but couldn’t become one because he was not a Canadian citizen.