11/10/2011 11:49 EST | Updated 01/23/2014 06:58 EST

Letter sent to Mounties claims to be from killer of B.C. teen, Taylor Van Diest

ARMSTRONG, B.C. - Someone claiming to be the killer of a British Columbia teenager has sent a letter to the RCMP containing a chilling threat and police want that person to contact them.

"It suggests the possible further violence against women," said Cpl. Dan Moskaluk as he described the letter sent to the Armstrong, B.C., detachment.

"We're not speculating as to its authenticity. We are simply looking at it to determine who may have sent it. Its contents, syntax, format, how it was received, are all details at this time that we are not divulging publicly."

Moskaluk said Thursday that the letter contains limited details about the crime and that police are trying to verify its authenticity.

He urged the author to continue communicating with police.

"This person or persons can contact the investigators by telephone or by another letter," he said.

"The investigators emphatically state that they want to create a dialogue with this individual, or these individuals, and this dialogue has the purpose of preventing any further violence."

A team of more than 30 officers has been working on the case since 18-year-old Taylor Van Diest was killed on Halloween night.

She had been badly beaten and died shortly after searchers found her near a popular shortcut along railway tracks through the usually quiet north Okanagan town of Armstrong.

Teens in the community of about 5,000 people were urged to travel in groups, stick to well-lit areas and leave word about any travel plans. That warning was repeated after the letter was received.

"We are asking that the general public to remain vigilant and continue to take extra personal safety precautions in our communities, particularly in the central and north Okanagan," Moskaluk said.

The results of an autopsy are considered "hold back" evidence to protect the integrity of the investigation, as are details of how Van Diest died or whether she was sexually assaulted.

Armstrong Mayor Chris Pieper said the letter police received Wednesday has people on edge.

"It does sound a bit weird and I think just since this case broke on Halloween we have to be a careful community, as if it happened in anybody's community. You have to be careful until the person or persons are caught."

Pieper urged people to travel in pairs and be careful where they walk.

"I don't think this is just for Armstrong, I think this is for the whole north Okanagan," he said of the area that's home to another 5,000 people.

Armstrong resident Fred Hooper said the community will remain on alert until someone is arrested.

"People are wondering, I guess, who would perpetrate a crime like that. It's hard to imagine anybody would do that but sadly, these people do exist."

Van Diest was found on the shortcut by a friend and a boyfriend.

A relative of the friend said they'd all planned to meet up.

"They were texting while they were walking and all of a sudden she didn't answer. And that's when they started searching," said the relative, who didn't want her name published.

She said the town had already been dealing with the deaths of three other young people in the last couple of months before Van Diest was murdered.

Five-year old Ava Mae Claassen and her four-year-old brother Austin died in a motor home fire last month near the Fraser Canyon community of Lytton and 18-year-old Cullen Rowan, a classmate of Van Diest, died in a workplace accident in September.

"I'd sure like to see that person brought to justice ... because if he has threatened that he's not finished that's really scary," the relative said. "Who's going to be the next target?"

Last week, the Van Diest family held a memorial service for Taylor, who has a twin sister, at a local arena.

They also honoured the three other young people who have recently died in Armstrong.