MALAD, Idaho (AP) - Authorities say a key piece of evidence has been unearthed from a brushy hillside about 12 miles east of here in the case of two Pocatello girls who disappeared nearly 29 years ago.
Police detectives teamed with Idaho State University students on Monday to excavate for a second time a spot near a remote gorge where hunters found the skeletal remains of Tina Anderson, 12, and Patricia Campbell, 15, in 1981. The girls disappeared in 1978 and the case remains unsolved.
Blackfoot police Lt. Paul Newbold would not say what the evidence was because of its potential significance to the investigation.
"One particular piece of evidence that we believe will go directly back to one of our suspects is damning," Newbold told the Idaho State Journal. "We believe this is the icing on the cake."
The girls vanished from a crowded Pioneer Days celebration in Pocatello's Alameda Park on July 23, 1978.
Forensic scientists from the state Crime Lab originally excavated the site in 1981, recovering most of Anderson's skeletal remains, including her skull, but also found a few of Campbell's bones. Anderson was identified through dental records in 1981; Campbell was identified in March of this year after months of DNA testing.
For years, the case remained largely inactive. But news coverage last summer led to renewed interest and the formation of a joint task force made up of police from five agencies in three eastern Idaho counties.
Another development came in December when an Idaho prison investigator provided still-undisclosed information about possible suspects.
Last week, Oneida County Sheriff Jeff Semrad said he had prime suspects in the cases and that the Idaho attorney general's office would assist in a future prosecution. Semrad has declined to give a timetable for making an arrest in the case.
The FBI is reviewing records from the original police investigation and provide ground probing sonar to help locate more evidence at the dig site.
At the site Monday, investigators said the evidence was discovered about 5 inches underground by Joseph Argyle, a retired Air Force colonel with a master's degree in archaeology who takes classes at Idaho State.
"I was told to look for clothing and bullets, but basically I'm looking for anything that doesn't belong here," Argyle said before making the find. "I think there is reason to believe this site may not have been completely excavated" in 1981.
Some former law enforcement agents from Pocatello have speculated the two killings may be linked to three other murders that happened between 1978 and 1983, including the slaying of 14-year-old Linda Smith, abducted and killed in 1981, and Cindy Bringhurst, 14, who disappeared from a baby-sitting job in 1983. Another set of remains, skull fragments of an African-American teenage girl found near where Anderson and Campbell were discovered, hasn't been identified.