Enlisting a Posse of Scientists

Three years ago this month, a hiker noticed his dog rummaging in the brush on a hilltop trail overlooking the town of Mammoth Lakes.

Drawing closer, the hiker saw his dog had found a human skull.

Later, an officer found a shallow grave nearby, with human remains contained in tattered plastic bags.

The body had apparently spent a winter under the snow. Time, and the bears and coyotes, had taken most of the flesh.

Police surmised only a few things about the body that day. It was a woman’s. She was short. And she wasn’t dressed for camping.

Their clues were few: a pair of high heels, size 1 or 2 jeans, a size 32A bra, a frilly red blouse, a furry Cold Air Design jacket and a Kmart Jaclyn Smith watch -- still running.

They would learn later from a pathologist’s examination that she appeared never to have had dental care, and she’d given birth at least once in her life.

Murder is a rare occurrence in placid Mammoth Lakes -- population 8,000 -- best known for the ski slopes popular with Angelenos. The Police Department has only 20 sworn officers. The woman was its third homicide in a quarter century.

The case fell to Sgt. Paul Dostie, 52, a genial detective with 20 years on the force.

Aware that his years in Mammoth Lakes hadn’t prepared him for the job ahead, Dostie reached out for help with the best tool he had: the Internet. Through e-mail, he slowly assembled an A-team of investigators, each with a different talent.

None worked in law enforcement. Instead, they were academics -- scientists who study how ancient peoples lived and died.

They were two anthropologists, a stable-isotope geochemist from Canada, two DNA analysts and a pioneer in American forensic skull reconstruction.

“That’s my claim to fame,” Dostie said dryly. “I know a lot of people smarter than I am.”

The case this small-town cop put together mined obscure scientific databases and analyses that have emerged only in the last decade with the mapping of the human genome and that still are the domain of a handful of anthropologists and geneticists. Some had never before been used in a U.S. criminal case, the researchers say.

“The stuff he’s done is really cutting-edge,” said Rich Longshore, a Los Angeles County sheriff’s detective who teaches homicide investigation and is familiar with Dostie’s case. “One thing about homicide investigations, it’s a free-play exercise. You have to always think of innovative ways to do things. He certainly has done that.”

Dostie sent samples from the woman’s body across the country.

The scientists studied her hair, teeth and bones, which can reveal clues about what she ate, what water she drank and where she spent her childhood.

Determining who this woman was began to consume Dostie.

*

The case got sidetracked as soon as it began.

Dostie first sent the woman’s remains to a forensic pathologist in San Francisco. The pathologist autopsied the woman and measured the skull. She could be Asian, he said.

U.S. Forest Service workers, not far from the campground, remembered seeing a tiny woman -- maybe Asian or Latina -- and a pudgy white man the previous fall. As her husband spoke to a forest ranger, the woman took the workers aside. In English, she told them that her husband was abusive. She feared him. The workers gave her a card from a women’s shelter.

It wasn’t clear that the corpse and that woman were the same, but Dostie had an artist draw composites of the couple, based on the workers’ descriptions.

For the next 15 months, Dostie put out fliers and even spread the word to websites for Asian mail-order brides. No leads.

Then he heard from a colleague who attended a crime seminar that new techniques in DNA analysis could determine genetic heritage.

He sent the woman’s femur to Florida-based DNA Print Genomics, hoping to learn her genetic background and thus where in Asia this woman was from. The company tested the DNA and found her to be Native American.

Dostie now had conflicting reports: Was she Asian or Native American?

He thought an anthropologist might help resolve the question. Using the Internet, he came upon Phil Walker, a professor at UC Santa Barbara. Past president of the American Assn. of Physical Anthropologists, Walker studies the health, diets and deaths of ancient peoples.

“The questions the police have are the same kinds of questions I’m interested in for earlier populations,” he said.

Walker promised to work the case without fee if Dostie promised to follow it to the end.

“I’ll admit to playing the we’re-a-poor-little-department-up-in-the-mountains-without-a-lot-of-m oney card,” Dostie said.

Walker re-autopsied the remains and, on some leathery skin, found two knife wounds that the San Francisco pathologist had missed.

Dostie had a cause of death.

New DNA extraction techniques and expanded databases of DNA samples allow scientists to learn much more about a person’s origin and lifestyle. “It would have been extremely difficult to do 10 or 15 years ago,” Walker said. Today, “we’re breaking the boundaries of the traditional limits of physical anthropology.”

But these techniques hadn’t come to many police crime labs. So Walker pointed Dostie to scientists who used them.

One was Henry Erlich, director of genetic research at Roche Molecular Systems in Alameda.

Dostie called.

“I don’t know him but he seemed like an interesting guy,” Erlich said, “so I tried to help him.”

Erlich analyzed part of the woman’s DNA -- the human leukocyte antigen genes, or HLA -- that could shed light on her ethnicity. He then compared those results with a newly created database, run by the National Institutes of Health, that contains HLA patterns of peoples around the world.

The result: her HLA type was much more common among Indians from southern Mexico and Central America than in other populations.

*

Walker had a hunch she was from Oaxaca, a state in southern Mexico, whose people are small and had migrated in huge numbers to California. “The first thing I wanted to know was whether or not she ate tortillas,” he said.

To find out, Walker called Henry P. Schwarcz, a geochemist at McMaster University in Ontario, Canada. Schwarcz studies the bones, teeth and hair of ancient Indians.

“You are what you eat,” Schwarcz said in a telephone interview.

Hair molecules contain traces of what people have eaten recently. Teeth molecules have trace elements of what a person ate as a child, when the teeth were forming.

The woman’s hair, Schwarcz said, showed she’d eaten large amounts of corn in the months before her death.

Her teeth showed that her childhood diet consisted of enormous quantities of corn -- to the exclusion of milk or meat, Schwarcz said.

This would point to a childhood spent in southern Mexico, the scientists figured, and would account for her small size.

The teeth also contained oxygen atoms. “Oxygen atoms come from water that you drink,” Schwarcz said. “The water you drink, for most people, is from local precipitation: rain.”

Oxygen atoms in rainfall differ by latitude across the world. The atoms found in the woman’s teeth were from a latitude where “the only place you could be on land [in North America] would be in southern Mexico,” he said.

Now Walker felt they needed to check DNA databases of Indians from across the continent, to see if any samples matched the woman’s.

Walker sent Dostie to David Glenn Smith, a UC Davis biological anthropologist. Smith has used DNA and other genetic data from modern and ancient humans to study the movement of peoples over the last 15,000 years.

He also maintains a database of mitochondrial DNA samples from Native Americans from Alaska to Argentina -- donated by geneticists and anthropologists since the early 1990s.

Large amounts of mitochondrial DNA are found in the cells of all humans, but it is passed down to them only by their mothers. Its abundance makes it extractable from even old remains. Because it doesn’t recombine with other DNA, it allows scientists to isolate a person’s maternal lineage and, if they are lucky, determine where a person is from.

“For forensic purposes,” Smith said, “it’s the first time we’ve had genetic information that was useful in associating an individual with a particular tribe or geographic region.”

In March, Dostie sent Smith the woman’s mitochondrial DNA results.

And there, among the more than 3,000 samples in Smith’s database, was one that closely matched the Mammoth Lakes woman.

It “was collected in the village of San Mateo Macuilxochitl” in Oaxaca, he wrote Dostie in an e-mail a few weeks ago. “There’s a reasonable chance that the victim has some connection with that village or one nearby.”

“I never heard of Oaxaca until this case,” Dostie said

*

San Mateo Macuilxochitl is a Zapotec Indian village of 3,000 people that predates the Spanish conquest. It lies in the Oaxaca Valley, east of the state capital of Oaxaca City. Its people have been peasant corn farmers for centuries, but in recent years they have also immigrated to the U.S., particularly California, Illinois and Michigan.

Bill Klitz, a public-health researcher at UC Berkeley, went to Oaxaca in 1994 to collect DNA for a study on the evolution of genes that regulate the immune system.

Klitz said he took blood samples from 33 villagers and added the mitochondrial DNA results to the UC Davis database.

“It’s not common to find a match,” Klitz said. “It really localizes things. It’s very narrowing.”

Matching mitochondrial DNA means the two women have a mother in common. It could be a mother, a grandmother or a great-great-great-grandmother.

But because the samples were taken with promises of absolute confidentiality, Klitz said he cannot divulge the name of the woman he sampled.

Undaunted, Dostie sent the skull to Betty Pat Gatliff, a pioneer in the field of forensic sculpture -- creating clay face models from decomposed skulls.

Gatliff, whose Skullpture studio is based in Norman, Okla., came up with a face that roughly resembles the drawing made of the woman who confided her fears to the Forest Service workers.

Dostie has put a rendering of the sculpture on fliers, and he distributed them to Oaxacan-immigrant leaders in Los Angeles.

A week ago, members of the Los Angeles-based Oaxacan Business Assn. went to San Mateo to pass out fliers and speak with villagers.

“I’m 99% sure she’s not from that village,” said Raymundo Morales, the association’s president, who was in San Mateo. “But there are other villages nearby, and we’re going to keep searching.”

Still, even with all they now know, he said, finding a nameless victim won’t be easy. “The Oaxaca Valley is vast and sometimes inaccessible,” he said.

Back in Mammoth Lakes, Dostie believes the dead woman is the same one who approached Forest Service workers. If so, her husband would be the prime suspect.

His job, as he sees it now, is asking the public for help.

“A 4-foot, 6-inch Indian woman with a fat, pasty white guy,” he said. “Someone has lived next door to this couple, and this is not the first incidence of domestic violence between them, I guarantee you. Someone’s called the cops on them.”

*

(BEGIN TEXT OF INFOBOX)

Clues to the killing?

Mammoth Lakes police are asking for the public’s help in identifying the body of a slain woman found buried near a hiking trail in May 2003.

The drawings at left are of a couple that U.S. Forest Service workers say visited the area in the fall of 2002. As her husband spoke with a park ranger, the woman approached workers to say that he was abusive and that she feared him. They gave her a card from a women’s shelter. Mammoth Lakes police believe the corpse may be that of the woman who asked workers for help. Mammoth Lakes police had a forensic sculptor design a model of what the victim may have looked like, right. Anyone with information about this woman or the couple is asked to contact (760) 934-2011, Ext. 0; or pdostie@mammothlakespd.org.

More on the victim

* Mexican Indian

* Age: 30 to 45 years old

* Height: From 4 feet, 6 inches to 4 feet, 9 inches

* With bad dental work

* Had given birth at least once

* She was wearing jeans, size 32A bra, fluffy red blouse, Bass size 5M shoes, Cold Air Design coat and a Kmart Jaclyn Smith watch that was still running.

Graphics reporting by Sam Quinones