Bones found 37 years ago linked to missing Sonoma County girls

This photo shows Francine Trimble, one of two girls missing since 1978 from their homes in Forestville. Trimble’s remains were identified in recent months, long after being found in 1979 in Mendocino County. This photo shows Francine Trimble, one of two girls missing since 1978 from their homes in Forestville. Trimble’s remains were identified in recent months, long after being found in 1979 in Mendocino County. Photo: Mendocino County Sheriff Photo: Mendocino County Sheriff Image 1 of / 7 Caption Close Bones found 37 years ago linked to missing Sonoma County girls 1 / 7 Back to Gallery

Two sets of bones found off Highway 20 near Willits nearly 37 years ago have been identified as the slain remains of a pair of teenage girls missing from Forestville since 1978, Mendocino County sheriff’s officials said.

For nearly four decades, the two cold cases — the missing girls and the discovered bones — remained unsolved and unconnected, waiting for technological advances to correct the mistaken belief that the bones were those of a male and a female.

This week, the families of 15-year-old Kerry Graham and 14-year-old Francine Trimble joined Sheriff Thomas Allman as he announced that the remains were the missing girls.

“We had largely resigned ourselves to never knowing why they disappeared,” said Will Walsh, Francine’s uncle. “We suspected that maybe foul play had been involved. We’re glad to know there’s a definite answer to that.”

The identification capped a long and tangled investigation into the bones, which included two exhumations for DNA analysis.

“I hope you would never believe we have forgotten this case,” Allman told the families during a Tuesday news conference. “This case is as active as it ever has been.”

Kerry and Francine, inseparable friends, went missing just before Christmas in 1978 after telling family members they were headed to the mall, Allman said. They were never seen again.

Nearly seven months later, two tourists driving on Highway 20 pulled over about 11 miles from Willits to stretch. One went for a walk and discovered the remains. The couple marked the spot with a soda can and contacted authorities.

The remains were sent to a forensic pathologist and an anthropologist.

“For some reason, and I don’t know why, in 1980, the remains were classified as a found male and a found female,” Allman said. “Both approximately age 14.”

The majority of the evidence was then sent to the FBI, where the case went cold for 20 years. In 2000, the bones were exhumed, with DNA collected, but the effort yielded nothing.

The remains were exhumed for DNA again in 2011 as the British Broadcasting Corp. and the National Center for Missing and Exploited Children investigated the cold case.

Finally, two months ago, the DNA was positively linked to Kerry and Francine, Allman said.

While the bones have now been identified, what happened to the girls remains an open question, Allman said. The remains yielded no clues about how the girls died, he said.

“We’re hoping somebody out there knows something,” he said. “This is a senseless case, a senseless tragedy.”

The girls’ relatives said the identification brought a fresh round of grief — and hope that those responsible would be found.

“We miss Francine,” Walsh said. “We regret deeply she never had a chance at a good life.”

Authorities are asking anyone with information to call a tip line at (707) 234-2100.

Jill Tucker is a San Francisco Chronicle staff writer. E-mail: jtucker@sfchronicle.com Twitter: @jilltucker