MOSCOW, Idaho -- This weekend marks a very somber and painful anniversary. On June 26, 1981, University of Idaho student Kristin David left her home on her bicycle. Days later, her remains were found in the Snake River. Her killer has not been identified.

On Friday, local and federal law enforcement from all over the region united with a plea for help to the public.

"Let me be clear, at this time, Kristin's murder is not a cold case," said Senior Resident FBI Agent Zach Schoffstall. "It's not going away, and we are more dedicated than ever to solving this case."

A case that stunned an entire region.

"Lewiston is a close-knit community where what happens to one is felt by all," said Capt. Jeff Klone with Lewiston Police. "Forty years ago, our community was rocked by tragedy. Kristin David, a 22-year-old (U of I) senior was last seen riding her blue, ten-speed bicycle on Highway 95."

Kristin was headed for the LC Valley.

"She was last seen alive near Genesee...where she was approached by a man in brown van," Klone said. "She never made it to her destination."

Days later, the missing person's case would become an official homicide investigation.

"On the Fourth of July 1981, Kristin's body began being discovered in the Snake River," he said.

Reports state her body had been dismembered, but the cause of death remains a secret kept by only law enforcement and Kristin's murderer.

"We never anticipated Kristin's case would go unsolved for decades," Klone said.

And that's what Friday's multi-agency press conference was all about, an attempt to perhaps number the days that continues.

"She deserves this...my parents deserve this," said Kristin's sister Anne. "I miss her laugh, her wisdom, her support. Kris was my sister, my friend, my counselor, and above all a beautiful soul."

She was taken by the ultimate evil. That's why both Anne and law enforcement are pleading with anyone who can help to come forward. They say even the seemingly smallest of details could lead to a break in this case.

Witnesses say the man in the brown van last seen talking to Kristin appeared to be about 30-years-old. They say he was roughly 5'10, 180 pounds with a brown or red-ish beard. The van appeared to be 'well-kept' with yellow license plates with dark lettering.

The FBI did address reports that Kristin's homicide may be tied to other unsolved crimes in the community.

"I'd be remiss if I didn't acknowledge that Kristin's case has long be associated with several other high profile murdered and missing person's cases in this area, during this same time frame," Schoffstall said. "We are not ruling out the possibility that Kristin's murder is related, but we are investigating Kristin's separately. This is all I will say about the other cases today."

Kristin's clothing and blue bicycle were never recovered. 

If you can help in any way, please call 800-CALL-FBI or visit tips.fbi.gov.

Kristin David