ORANGEVILLE, Ont. - Police say the "cold-blooded killer" responsible for the slaying of an Ontario nurse may have moved away from the community or at least kept to himself following the crime.

Provincial police called on the FBI to help shape a suspect profile in the case of slain Orangeville woman Sonia Varaschin.

The 42-year-old nurse was reported missing in August and her body was found in a wooded area a few days later.

Before police provided an update today into what was learned from a three-day "investigative summit," Varaschin's mother made a heartfelt appeal for anyone with information to call investigators.

Michele Varaschin says nothing can describe the pain her family is feeling, especially during the holidays.

"This Christmas, there will be an empty setting at our table where Sonia used to sit with her bright smile, talked, joked and just enjoyed Christmas with all her family," she said.

"I wish this feeling on no one."

Det.-Insp. Mark Pritchard of provincial police said the killer was likely familiar with the Caledon area where the body was found.

The killer may have increased his alcohol or drug use and likely shied away from others after the crime, Pritchard said Thursday, adding investigators have received some 460 tips from the public.

"Someone familiar with the killer may recognize these traits, and we are appealing to that individual or those people to come forward and call the police immediately," Pritchard said.

"I'd say he's a cold-blooded killer. He killed somebody who we'd consider a very low-risk victim and (he) engaged in some very high-risk behaviours."

Criminal profilers from the FBI's Behavioural Analysis Unit in Virginia recently met with investigators on the case -- along with experts from the provincial police and RCMP.

The meeting -- described by police as an investigative summit -- also included senior homicide detectives from the provincial police force as well as from the York Region, Ottawa and Toronto forces.

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, Pritchard told a news conference in September.

In September, investigators urged the public to think back to the last days of August, when the killer may have come home with unexplained stains on his clothes or boots.

Varaschin was reported missing on Aug. 30 after she failed to show up at work. Her blood-stained car, a white Toyota Corolla, was found in an alley the same day.

Police also found blood inside and outside her home, and had asked the public to be on the lookout for blood-stained bedding.

Days of ground, air and trail searches of the Orangeville area, which is predominantly rural, failed to find traces of the missing woman.

Remains discovered days later in a wooded area in Caledon, about 12 kilometres from Orangeville, were later confirmed as Varaschin's.