A B.C. man has been arrested and charged in the Halloween night murder of Armstrong teenager Taylor Van Diest last year, and his father has been charged with obstruction of justice in connection to the case.

Former Cherryville resident Matthew Stephen Foerster, 26, was arrested Wednesday afternoon at a motel in Collingwood, Ont. and charged with second-degree murder in the 18-year-old's slaying.

His father, 58-year-old Stephen Roy Foerster, has been charged with obstruction of justice and accessory after the fact.

Van Diest was found unconscious and fatally wounded in the bushes near the railroad tracks that run through her small Okanagan community on Oct. 31. She died a short time later.

At a press conference Thursday at Armstrong Town Hall, Insp. Brendan Fitzpatrick announced the arrests, but said police would still not be commenting on the cause or circumstances of the teen's death.

The results of an autopsy performed on Van Diest were never released.

"We can't go into detail in respect to the circumstances obviously because it's before the courts now," Fitzpatrick said, adding only that there is "no indication that Van Diest knew the suspect."

Van Diest's mother Marie told reporters after the announcement that news of the arrests was bittersweet.

"We finally can direct our anger at a face," she said. "Now I know what evil looks like."

Police released images of the younger Foerster, who has no prior criminal record, in hopes that new witnesses will come forward and help them piece together the events leading up to Van Diest's death.

Fitzpatrick confirmed Foerster is also a suspect in two unrelated crimes, including a 2004 assault and home invasion and the April 12, 2005 sex assault of a Kelowna escort.

He has been charged with half a dozen counts, including sex assault, unlawful confinement, break and enter and assault with a weapon, in connection to those incidents.

Thursday's announcement was the first update shared in the case for five months. In November, investigators revealed they had DNA evidence linking Van Diest's death to an unsolved sex assault in the Okanagan.

The same month, police received a letter from someone claiming responsibility for the Armstrong murder and warning of more violence towards women. Fitzpatrick said the letter "heightened fear in the community," but police are still working to determine its authenticity.

"We're talking it very seriously. The source of that letter is still under investigation and we're pulling out all the stops to get to the exact source of who wrote that."

Van Diest's boyfriend was the one who discovered her lying gravely injured near the railroad tracks. Friends say the last words from the deceased, who was dressed in a zombie costume the night she died, were in a text message to him that said "I'm being creeped."

Mounties say they are continuing their efforts to establish a timeline of Matthew Foerster's activities the night of the murder, and are asking anyone with information to call a tip line set up specifically for the case at 1-888-266-4264.