5 People Vanished Along the Snake River Beginning in 1979: Will Police Finally Catch a Serial Killer?

On the morning of April 28, 1979, 12-year-old Christina White went to the Asotin County Fair in Eastern Washington State before biking over to a friend's house. A few hours later, White called her mom crying, saying she was feeling overheated. Her mom suggested she cool down with a cold cloth and then come home, a few blocks away.

White never made it home and was not seen again.

Within three years of White's disappearance, four more young people went missing — three of them found murdered — in the Pacific Northwest's Lewis Clark Valley, which straddles Washington and Idaho.

The disturbing case remains unsolved, and is the subject of next Monday's episode of People Magazine Investigates. Titled "Valley of Death," the episode airs June 27 at 9 p.m. ET on Investigation Discovery and also streams on discovery+. (An exclusive clip is shown below.)

On June 26, 1981, college student Kristin David, 22, was riding her bike from Moscow, Idaho to Lewiston, Idaho, when she vanished. Eight days later, her dismembered remains were found in garbage bags by a fisherman along the shore of the nearby Snake River, near Clarkston, Wash.

"I just couldn't imagine what Kristin went through," David's older sister Anne Mackey says in this week's issue of PEOPLE. "It was a real-life horror story happening right outside the doors of our homes."

Then, on Sept. 12, 1982, the community of Lewiston would suffer another blow with the disappearance of three residents on the same day.

Stepsisters Jacqueline "Brandy" Miller, 18, and Kristina Nelson, 21, vanished after leaving Nelson's apartment to walk to a grocery store nearby the Lewiston Civic Theatre, where both young women had worked as janitors. Nelson, an aspiring artist, left a note for her boyfriend letting him know they would be home soon.

They never made it.

That same evening, 35-year-old Steven Pearsall, another theater employee, disappeared after being dropped off at about midnight by his girlfriend at the Lewiston Civic Theatre. He went there to use the building's laundry machines and to practice his clarinet.

After police began investigating, they found Pearsall's clarinet at the theater, but his laundry was missing.

Police soon received several reports of a man and two girls hitchhiking outside of Lewiston, but nothing came of those tips. Police also thought that Pearsall, Miller and Nelson may have left the area to join a cult. But on March 19, 1984, the remains of both Miller and Nelson were discovered down a hillside off Highway 3, about 40 miles outside of Lewiston. The coroner ruled their deaths homicides.

Want to keep up with the latest crime coverage? Sign up for PEOPLE's free True Crime newsletter for breaking crime news, ongoing trial coverage and details of intriguing unsolved cases.

Detective Jackie Nichols of the Asotin County Sheriff's Office hasn't given up hope of solving these decades-old cases.

"These cases generated a ton of interest in our community, a lot of media coverage ... and rumor over the years," says Nichols. "My goal is to find some justice."

Another person who hasn't given up is Nelson's cousin, Gloria Bobertz, who started a Facebook page aimed at getting tips about the slayings and disappearances. Bobertz, who is working alongside Nichols, says the duo won't stop until they find answers.

"We're not going to give up," she says.

If you have information that could help the investigation into any of these cases, please contact 800-call-fbi, tips.fbi.gov or the Asotin County Sheriff's office at 509-243-4717.

See more on the disturbing mystery of five disappearances along the Snake River on People Magazine Investigates ("Valley of Death"), airing Monday, June 27, at 9 p.m. ET on Investigation Discovery and also streaming on discovery+.