Investigators are set to begin collecting voluntary DNA samples from men who knew or had contact with Sonia Varaschin around the time of her murder.

The purpose is to narrow the pool of potential suspects as police continue to hunt for the person who killed the Orangeville nurse last August.

Varaschin's body was found in a wooded area in Caledon but police believe the 42-year-old woman was slain in her home a few days earlier.

Ontario Provincial Police detectives are planning to speak to reporters Wednesday about a new phase in the investigation, which involves the widespread collection of DNA samples from men over 18 years of age who may have had contact with Varaschin.

Though the men will have a legal right to say no, detectives will ask them to willingly submit a DNA sample by having their inner cheek gently scraped with a cotton swab.

Police have rarely used this tactic as it is often criticized as an infringement on people's right to privacy.

However, authorities say samples taken from people who have been ruled out as suspects will not be stored or kept on record, meaning they won't be used again in future investigations.

"Individuals providing a DNA sample are asked to sign a consent form and can contact legal counsel for advice prior to signing," police said in a news release Tuesday. "The sample and all associated documentation are destroyed once deemed not to be a match to this investigation. Providers of samples receive written confirmation that this has occurred."

Suspect profile

In an another rare move, investigators sought the help of FBI criminal profilers, who created a suspect profile, and senior homicide detectives from outside law agencies, including Toronto police.

Police believe Varaschin's killer was likely familiar with the Caledon area where her body was found, may have increased his alcohol or drug use and likely shied away from others after the killing.

Police have previously said the killer wore a specific type of boot sold only at Mark's Work Wearhouse.

The boots are a men's size 10 or 11, sold under the Wind River or Dakota brand name, police said last September.

Police said Varaschin's killer may have moved away from the community or kept to himself following the crime.

With a report from CP24's Sue Sgambati and files from The Canadian Press