OKLAHOMA CITY — Sandy Rea left a friend’s house one September night to visit her cousin, who worked at a Shawnee bowling alley.

From there, the 17-year-old with wispy dark blond hair and a smattering of freckles across her nose called a friend to ask for a ride to a party. The friend’s parents wouldn’t allow their daughter out that night.

That was 1984. Sandy’s family never saw her again.

Almost three decades have passed. Since that phone call, she has remained silent to all who loved her.

But for the missing like Rea, there is a voice.

Angela Berg is an anthropologist with the state medical examiner’s office.

Through science and old-fashioned detective work, her goal is to connect unidentified remains with the faces and names of those who have been reported missing.

“I’m the last voice for these victims,” said Berg, who was hired in 2010.

Her predecessor and mentor, Clyde Snow, is a forensic anthropologist and longtime consultant to the office approaching his mid-80s and inching slowly toward retirement after a productive and storied career.

Snow splits much of his time between Latin American countries, helping teams identify via anthropological and DNA analysis thousands of victims of political unrest. Their bodies lay in mass graves in Argentina, Guatemala and elsewhere.

Back in Oklahoma, Berg has begun to take over where Snow left off.

The smell of decomposing remains in the aging facility wafts into the hallway near the morgue as Berg talks about the backlog of unidentified remains more than 40 years and 128 cases deep. Some of the mostly skeletal remains are stowed in labeled boxes in a hallway closet in the medical examiner’s cramped Oklahoma City office.

In an office that considers itself chronically underfunded, ordering new boxes to organize the older skeletal remains was not an insignificant victory, she said.

There is new science to be applied to the remains, new databases in which to enter the data collected from these lonely dead.

On any given week, about 10 newer bodies at the medical examiner’s office require special attention because each lacks an identity.

And then there are cases like Rea’s. There is no body. There are no answers.

A piece of a human skull found in the bottom of the North Canadian River is what connected Berg to Sandy Rea’s family in July. A high school friend of Rea’s was searching for anything that could help the case on the National Missing Persons and Unidentified database. Also called NamUs, the public database was launched in January 2009 to help law enforcement, the community and medical examiners connect those reported missing with unidentified remains.

The partial skull was pulled from the river in November 2007 in Pottawatomie County, the county from which Rea disappeared. It most likely belongs to a female age 14 to 30 years of age, Berg said.

The database entry on the skull listed contact information for Berg. That led to a string of emails and connected Berg to Rea’s family members.

She collected DNA samples from Rea’s mother and sister in July by swabbing the insides of their mouths.

Berg’s demeanor is not what one might expect from someone who spends her days with the dead. She smiles easily, and she listens.

Rea’s family members appreciated the warmth she exuded as she listened to their ordeal, said Brandy Davis, Rea’s sister.

Berg also asked for copies of Rea’s dental X-rays, and details like clothing size, shoe size and medical information to enter into the NamUs database.

After decades of dead ends and clashes with law enforcement over the handling of the case, the forward movement felt good, Davis said.

Combined with a Facebook page that has fostered an online community determined to help find out what happened to her sister, Davis is holding out hope for a resolution.

“I feel like we’re about to break this wide open,” she said. “I truly believe that.”

Now, the family is waiting for their DNA samples to be cross-checked with the skull’s sample, as well as DNA samples from Jane Does across the country.

In the meantime, there is much to be done. Berg’s work has taken her all over the state, into fields, a cave and the bottom of a sewer, attending to unidentified bodies in every imaginable condition.

It’s not work for the faint of heart.

To piece together identities, she prepares the remains for DNA analysis. Preparation involves simmering bones at a low temperature in water and laundry detergent or sending blood samples to the lab.

When possible, she takes fingerprints or arranges for dental impressions. That information is forwarded to the appropriate agency or entered into databases for the missing and unidentified.

She looks for marks on bones that could indicate trauma and a cause of death. On a recent day, an unassuming box containing the head of an unidentified man sits on her small corner desk. It awaits the attention of her colleague Harvey Pratt, an Oklahoma State Bureau of Investigation agent who will build a clay model of the man’s face.

“Once he does the reconstruction, we’ll take photographs and we’ll put it on the NamUs database,” Berg said.

Berg is a veteran operating room nurse with a master’s degree in anthropology. She’s pursing a Ph.D. in biological anthropology at the University of Oklahoma.

The process of identifying human remains can be slow going, but there have been bright spots in providing families closure often the best thing loved ones of the missing dare to hope for.

In February 2011, when skeletal remains were found encased in concrete at the bottom of a Muskogee sewer, Berg worked with other scientists and a team of archaeologists to identify the woman as Carol Grannon. Authorities think a man she knew strangled her in 1999 and enlisted an accomplice to help dispose of her body.

The family, including Grannon’s ex-husband and their two children, along with the Muskogee community, pulled together to thank Berg, law enforcement and everyone who played a hand in retrieving and identifying the missing woman.

Those are the kind of moments that keep Berg going.

“That really makes it all hit home,” she said. “It’s not just boxes of bones. These are real people.”

When Davis was 9, her sister Sandy would braid strands of her hair and sing a twangy version of Tanya Tucker’s “Delta Dawn.”

The song’s chorus and that memory have stayed with Davis all these years: “Delta Dawn, what’s that flower you have on? Could it be a faded rose from days gone by? And did I hear you say he was a-meetin’ you here today, to take you to his mansion in the sky?”

“I don’t think there are any hopes other than finding her remains,” Davis said. “We just want to know without a doubt, she’s gone.”