The Crown prosecutor in the trial of Aubrey Levin finished his closing arguments in a Calgary courtroom Tuesday, wrapping up final arguments from both sides.

Levin, 74, is a former forensic psychiatrist who is charged with nine counts of sexual assault against male patients who had been ordered by the courts to see him.

The closing arguments have wrapped up in the sexual assault trial of former court psychiatrist Dr. Aubrey Levin with the Crown defending the testimony of its star witness. (CBC)

On Monday, defence lawyer Chris Archer tried to discredit the crown's primary witness, who has a long criminal history and was on probation at the time of the alleged assault.

The witness taped the alleged sexual assaults with a hidden camera in 2010.

The videos show Levin undoing the man's belt and jeans and appearing to fondle him.

Crown prosecutor Bill Wister tried to convince the jury Tuesday that the witness was telling the truth.

Wister told the court there is no sugar coating the witnesses' past.

"He is who he is," said Wister.

The Crown told the jury the videos speak for themselves.

Wister described the victims as "sitting ducks" who were preyed upon by someone in a position of power.

"What you're seeing in the videos is sexual assault," Wister said. "If it happened only once it's still an offence."

Levin's explanation

The only time the jury heard Levin speak was in his videotaped statement to police after his arrest. The psychiatrist said he was performing medical procedures on patients to help them with sexual dysfunctions.

Wister said such a test would be very unusual and would typically be used on patients with severe spinal shock, citing testimony from a University of Toronto urologist.

"It's my submission to you that none of these nine people were in severe spinal shock," he said.

Court of Queen's Bench Justice Donna Shelley is to give her final instructions to the jury on Friday.

With files from The Canadian Press