A prosecutor said Monday he will seek an indictment against Ward Weaver, a suspect in the disappearance of two Oregon girls. The remains of one girl were identified Sunday.

"We will present a case to the grand jury and we will seek an indictment" against 39-year-old Weaver, said Greg Horner, chief deputy district attorney for Clackamas County.

Horner would not say yet whether he will seek the death penalty. The prosecutor said he didn't expect to bring charges against anyone else in the case.

Two bodies were found over the weekend hidden behind Weaver's rented home. One of them was identified as 13-year-old Miranda Gaddis, one of the missing girls. An autopsy is being conducted to determine whether the other is that of Ashley Pond, who was 12 when she disappeared.

"We expected this," Tim Lyons, Weaver's attorney, said of the announcement. "We are going to await the return of the indictment and see what the charges are and proceed from there."

Weaver has been in jail since Aug. 13 on an unrelated rape charge.

The girls vanished last winter, prompting a nationwide search that ended over the weekend just a few hundred yards from the apartment complex where they both lived.

Miranda's body was found in a shed behind the Weaver home. Another corpse was discovered by investigators in a barrel that had been placed beneath a concrete slab poured by Weaver after the two girls disappeared.

FBI investigators returned to the property on Monday with high-tech equipment, a back-hoe, shovels and pickaxes to search for any evidence that might be hidden in the earth.

FBI spokeswoman Beth Anne Steele said investigators didn't believe there were any more bodies on the property, but said investigators "do want to clear the property to make sure there's nothing else."

She refused to say how agents knew to look in the shed and beneath the slab for bodies.

"That's not something I'll comment on," Steele said.

Investigators over the weekend pitched large white tents over the shed and over the concrete slab and began to work inside them.

A device called a ground penetration system was brought to the site on Monday. Steele explained that the high-tech system can look beneath the soil to determine whether it had been disturbed.

Steele said investigators uncovered three barrels but they contained only dirt. She also said investigators were nearly finished processing potential evidence inside the house.

The girls' relatives said Monday they were frustrated that the bodies were found so close to the girls' apartment complex.

"It makes a pit in your stomach. I get angry because she was right there the whole time," said Terry Duffey, Miranda's aunt.

"Detectives and police stood out here all hours with posters and they were right here all along," she said. "They came in and out of that driveway 100 times and they were right there, I mean right there and we couldn't do anything."

A security fence erected by police around the property had become a makeshift memorial Monday -- festooned with flowers, teddy bears, and notes in which people expressed their grief.

Throngs of mourners have been visiting the site, including some family members.

"We are never going to forget what happened. This is going to hurt my daughter for the rest of her life," said Wes Duffey, Miranda's grandfather.

"We know she's dead," he said. "We have an answer to that. The next question is, who done it."

Weaver weeks ago said he was a suspect in the FBI investigation, but denied any involvement.

Horner said Monday that Weaver had consented to the search that resulted in investigators finding the two bodies.

Weaver was arrested on Aug. 13 on charges of raping his 19-year-old son's girlfriend. His distraught son, Francis Weaver, told emergency dispatchers after the alleged rape that his father had killed Ashley and Miranda.

"I'm very glad that Ward will never be able to hurt anyone ever again, nor destroy any more lives," Francis Weaver told KATU-TV in Portland late Sunday.

Last summer Ashley had accused Weaver of molesting her, but he denied the allegations and was never charged. Family members and friends have said they had a close, and at times inappropriate, relationship.

Ashley's family last saw her on Jan. 9 eating breakfast with her younger sister before school. On March 8, Ashley's friend Miranda also disappeared from the same low-income apartment complex south of Portland.