Police, forensic experts detail investigation as Christopher Duke sexual assault trial continues

WARNING: This story contains details some readers may find distressing.

The Crown continued to lay out its case against Christopher Duke in Regina Court of Queen's Bench Thursday.

Duke is accused of one count of sexually assaulting a person under the age of 16. He has pleaded not guilty.

The assault is alleged to have occurred at a home in the east of Regina on the evening of July 1, 2019.

At the time of the alleged assault, the alleged victim was a 12-year-old girl known to Duke.

The trial is being held under a publication ban that prohibits the publication of any information that could identify the complainant.

Thursday saw forensics experts and police officers take to the stand to provide details on the police investigation into Duke.

Const. Taylor Revler told the court that he was the first officer on scene after being dispatched to what was described as a sexual assault by a man named Christopher Duke.

When Revler pulled up to the location, he immediately saw a man walking in the complex's parking lot toward a white truck.

Revler asked the man who he was and the man confirmed that he was Christopher Duke, even offering to show the officer his ID.

Revler immediately detained Duke as more police arrived on the scene and began to investigate.

Duke was informed of his rights and told Revler that he wanted to talk to a lawyer. When Duke attempted to continue talking, Revler told him to stop as the man had previously said he wanted talk to counsel.

Revler formally placed Duke under arrest for sexual assault a short time later and eventually transported him to the Regina Police Service cells.

The patrol officer then spent the day monitoring the complainant and her mother as a sexual assault kit was completed at Regina General Hospital.

He would eventually go with other investigators to seize evidence from the scene of the alleged assault.

The evidence included a grey hoodie and khaki shorts, as well as bed sheets and a pair of board shorts Duke was wearing at the time of the alleged assault.

Those shorts appear to be central to the Crown's case. Revler brought them into court to display them.

The court has previously been told that tests conducted by investigators found DNA from the complainant on the shorts.

Cpl. Mark Golaiy also took the stand on Thursday.

In 2020 he was a member of the Regina Police Service's forensic identification unit.

He was the officer that collected DNA sample from Duke in 2020 as part of the investigation.

Vashni Skipper and Laurie Karchewski, forensic specialists with the RCMP, testified on Thursday afternoon.

Karchewski ran through the tests she conducted on the items seized at the scene of the alleged assault.

She testified about a sample taken from the swim trunks seized at the scene of the alleged assault that was found to have DNA sample consistent with two people.

Karchewski said one of the samples matched with the DNA of the complainant, with the odds of it being a random match being 1 in 24 quintillion.

She was unwilling to speculate on how the DNA of the complainant could've gotten to the inside of the shorts. Karchewski said she could not discount the possibility that the sample was transferred from another piece of clothing.

Karshewski also conducted tests on samples collected during a sexual assault examination of the complainant.

She said that a swab taken from the vaginal area of the complainant was found to have the presence of male DNA. However, due to the type of test that was performed, they could not come up with a male DNA typing profile due to the relatively low amount of male DNA in comparison to the female DNA of the complainant.

A second test, known as a YSTR test, was conducted on the sample. This test was carried out by Skipper.

The YSTR test essentially ignores the presence of female DNA in a sample and only looks at the male DNA. That allowed the forensic specialists to produce a profile for the male DNA detected on the vaginal swab.

That profile matched the DNA from Duke's blood sample, Skipper testified.

The Crown believes it will finish presenting evidence on Friday morning.

The trial was originally scheduled to last four days, from Monday to Thursday.

It will now continue through to at least Monday, with the defence preparing to have their own DNA expert testify.