(CBC) -- Investigators looking into the murder of Sonia Varaschin said Tuesday that they would seek voluntary DNA samples in the hopes of catching the Orangeville nurse's killer.
The Orangeville Police Service and the Ontario Provincial Police said that "DNA was recovered" during the course of the eight-month investigation.
Police said they would be contacting a select group of males who were 18 and older at the time of the offence and asking for a voluntary submission.
Investigators are expected to compile a list in the next few days, but the process is expected to continue for several weeks.
"I think it's important for the killer to understand we have your DNA and it's only a matter of time before we find out who you are," Const. Peter Leon told CBC News.
Police said there was no obligation to provide the sample and that participation was voluntary. The investigators also said that the samples would only be used to compare DNA recovered during the investigation, and that the sample as well as other documents would be destroyed if there was no match.
Police also asked the public to alert them of anyone "who begins to exhibit a change in behaviour, who may be acting strangely or may have abruptly moved as a result of the notification of this DNA canvas."
Leon said this kind of search for DNA has been used before - when Holly Jones, a young Toronto girl was murdered in 2003 - and it led them to her killer.
Varaschin, 42, went missing in late August. Her white Toyota Corolla was found at Orangeville Town Hall the same day her disappearance was reported. The car was bloodstained and both front doors and the trunk were open.
A bloody crime scene was also found at her Orangeville townhouse complex, but police said there was no sign of forced entry into the home, and police don't believe her killing was random.
Varaschin's remains were found by someone walking through the woods about 13 kilometres east of Orangeville eight days later.
Last week Varaschin's mother told CBC News that she was growing frustrated by the lack of progress in the investigation.
"I find that after so many months absolutely nothing has come out. You get angry..." said Michele Varaschin.