A Squamish, B.C., teenager who disappeared after leaving a house party on Bowen Island last year likely met with foul play, RCMP officials announced Wednesday.

Jodi Henrickson, who would have turned 18 last week, vanished in the early morning hours of June 20.

RCMP officials said Wednesday that they have classified the case as a homicide.

They said they believe people on Bowen Island have relevant information but are unwilling or afraid to come forward.They said others have refused to cooperate with authorities.

Investigators plan to return to the island in coming days to re-interview residents.

The wait, meanwhile, for Henrickson's parents has been agonizing. In an interview with CTV News, the parents said they are frustrated that people are keeping critical information from police.

"Did not one person on Bowen see her?" said Henrickson's mother, Nancy. "Somebody had to have seen something."

In August, Henrickson's ex-boyfriend, Gavin Arnott, told CTV that the last time he saw Henrickson they had been arguing in the middle of the road between 4 a.m. and 5 a.m.

"I guess she walked off. I walked off without looking back," he said.

Arnott has a history of violence against Henrickson. He was convicted of assaulting her two weeks before the party.

After Henrickson vanished, Arnott was interrogated by police for hours, then released.

An intensive search of Arnott's father's property was conducted last July.

Search and rescue crews scoured the rest of the island. Nothing was found.

Henrickson's parents remain optimistic there will be a break.

"I believe we will get an answer," Nancy Henrickson said. " I know we will get an answer."

Anyone with information should call 604-892-6100 or Crimestoppers at 1-800-222-8477.

With a report from CTV British Columbia's Lisa Rossington