In a first, Edmonton police have used DNA to create a composite sketch of a 2019 sexual assault suspect

An approximate image of a man who in 2019 violently sexually assaulted an Edmonton woman and left her unconscious in a field has been generated from DNA.

Edmonton Police Service has never before used DNA phenotyping to create an image of a suspect.

But in releasing the image of the man on Tuesday, EPS said investigators over three years had not found a DNA match or witnesses, CCTV or public tips that helped.

"I'm left with just sitting there and waiting for this suspect's DNA to show up at another crime scene. Or perhaps this person will get convicted and then DNA is uploaded into the DNA database," Det. Colleen Maynes, the officer in charge of the file, told reporters Tuesday morning.

"I don't want to wait. It was a vicious assault. Random stranger assault. And the survivor deserves justice, as well as the public."

WOMAN FOUND INJURED

On March 10, 2019, an injured woman wearing only a shirt was found calling for help in north-central Edmonton.

She had been followed and attacked by a man waiting at a bus shelter on the west side of 101 Street north of 117 Avenue.

The man was believed to have fled west from the scene.

The victim awoke in a field near St. Basil and Spruce Avenue schools.

She described her attacker as about 5'4" tall and having an accent. She could provide few other details, as he had been wearing winter clothing including a scarf and toque, Maynes said.

DNA from the scene was sent to the RCMP's national database, but did not match with any other crime or offender.

It also did not match with any DNA uploaded to a couple of U.S. genealogy systems.

"The familial matches that came up are so distant that we're not able to do genetic genealogy for that. Which led me to Parabon, because they can create a computer-generated image of what this person looks like," Maynes explained.

• Woman sexually assaulted, left in state of undress in Edmonton field: EPS

HOW PHENOTYPING WORKS

The image of the man was generated by Parabon NanoLabs, a DNA technology company in Virginia that specializes in advanced DNA analysis.

Phenotyping is sometimes used to try to predict physical appearances and ancestry from unidentified DNA evidence. It has been used by Calgary and Saskatoon police, according to Maynes.

In the Edmonton case, Parabon concluded the suspect – as the victim reported – is Black. The profile predicted he also is of entirely African descent. He is believed to have dark brown or black hair and dark brown eyes. Parabon's analysis predicted the skin and hair colour with more than 99 per cent confidence, but eye colour with 50 per cent confidence. 

Suspect sketch generated fr... by CTV News Edmonton

The composite sketch is a "scientific approximation," EPS reminded the public, not an exact replica.

It also has limitations: Parabon uses a default age of 25 and body mass index of 22, and cannot weigh how much environmental factors, such as smoking, drinking and diet, may affect appearance

Phenotyping also does not predict non-environmental factors, like facial hair, hairstyle, or scars.

So the man wanted by police could be older, have a different body composition, or look stylistically different from the sketch produced by Parabon.

"I can't say how accurate it is until we identify him and maybe compare the pictures," commented Maynes.

Parabon claims to have helped identify more than 230 persons of interest since 2018. 

'LAST RESORT'

EPS said it is aware of "the impact" the image could have on marginalized communities, but decided to release it because of the severity of the assault, the opportunity to further a cold case, and in the interest of public safety.

Spokesperson Cheryl Voordenhout said EPS consulted community before releasing the image.

"We want to make sure that people don't feel that this is a generalized image of someone from a certain ethnicity," Voordenhout noted.

An IT ethics expert argued the technology "doesn't provide useful information beyond the stereotype."

"It gives the EPS a justification for surveilling any person they get a tip about and collecting discarded DNA on any person they get a tip about," said Joshua Stein, a Georgetown University postdoctoral research fellow. "That's incredibly dangerous, that's a recipe for straightforward racial profiling, straightforward violation of charter of rights."

Maynes compared the DNA-generated image to a composite sketch by an artist.

"It's a technique," she said.

"Anyone identified, they are a person of interest and we do conduct additional investigative steps. Any tips that come in, they're leads. They're investigative leads that we need to follow up. By no means, we're not going to be running out and arresting every single person that's identified as looking like this image."

Anyone with information about the suspect or assault is asked to contact Edmonton police at 780-423-4567 or Crime Stoppers at 1-800-222-8477.