He was just a boy, 13 or 14 years old at the most.

His clothes appeared homemade. In his dusty backpack, which bore a soccer player's image, he carried a plastic bottle. Someone or something had taken one of his shoes.

His remains were found last summer near the Mexican border -- just a skeleton, really, and not even a complete one; a femur was missing, and so were his hands and feet. No one knew the boy's name, and it was anyone's guess how he had died, or when.

The only clear thing was that he was a Mexican who had crossed the border illegally and perished, maybe from dehydration and the heat, maybe at the hands of a killer.

Today, the boy's bones are laid out in a lab at Baylor University in Texas, behind a door that says "Secure Area -- Do Not Enter." For Lori Baker, a young professor at the school, the skeleton is an inspiration and a cause. She is determined to return the boy's remains to his family and, eventually, to do much more.

Baker, 32, a forensic anthropologist and an expert in DNA, is in the first stages of a project she hopes will identify some of the scores of other immigrants who die anonymously every year along the 1,950-mile border the United States shares with Mexico. The goal is to reunite them with their families and ease the uncertainty of parents and relatives who have waited, in some cases for years, for news of their loved ones.

"Nobody cares about illegals -- there was a sheriff who wanted to keep the Mexican boy's skull for his desk," Baker said. "But my grandmother was a migrant worker in the Depression, and it just disturbs me knowing a relative of hers might've died without her being able to find out about it."

Baker's project is a mammoth undertaking. More than 300 migrants die each year in the United States along the Mexican border, about one-third of them anonymously -- and those are just the ones reported to the U.S. Border Patrol.

They die in the sun-baked deserts of Arizona, where summer temperatures can reach 120 degrees, and in the sprawling mesquite and cactus scrublands of Texas, where a rancher might find a body weeks or months later. Some bodies are pulled out from the Rio Grande. Some are found on land, all but mummified after having been baked white in the dry heat.

Those whose identities are known are usually turned over to Mexican authorities. The others are buried in particleboard caskets in paupers' graves.

Often, they end up in graveyards such as the San Felipe Cemetery in Del Rio, a border town 130 miles west of San Antonio. Some of the paupers are buried on a wind-swept hillside littered with cigarette butts and candy wrappers and wreaths that have fallen from the tripod mounts left by relatives. A sign on a tree says, "No Dumping."

Among plots with headstones, the grave sites of the unknown can be easy to miss. The graves are marked only by index cards, sloppily typed, set in cheap metal frames behind dirty cracked windows. One of them reads:

Unknown Found at Seminole Canyon -- Rio Grande and Pecos River

Born: Unknown

Produced 8/22/1991

Don's Funeral Chapels

A few feet away lies another plot whose marker has been lost or removed. Only San Felipe's caretaker, Jesse Cardenas, remembers who is buried there.

"It was a young girl, maybe 13," said Cardenas, 76, a World War II veteran. "She was buried maybe eight or nine years ago. She drowned in the Rio Grande. I remember her because it's the only young girl we've buried up here . . . Like God said, dust to dust, that's the way it is."

On its face, Baker's plan is simple enough: Exhume the corpse, take a DNA sample from a tooth or a bone fragment, enter it into a database and invite the relatives of migrants who have disappeared to send in their own DNA in the form of a saliva swab or smear of blood. Given time and enough samples, she hopes to be able to make some matches. With local officials' cooperation, she might even be able to take DNA samples before remains are buried.

But the logistical obstacles are formidable. One challenge is getting out the word to migrants' families, most of them Mexicans, who may have limited access to the Internet and other sources of information. Another is overcoming the suspicions of families, often distrustful of the government, that any information offered about their migrant relatives could be used by authorities against them or their relatives.

"People are willing to make that call, but only as long as it's non-threatening," said Andrea Kauffold, editor of the Farmworker News in Buda, Tex., a newspaper for migrants published in Spanish and English.

Nonetheless, many families do search for their relatives, often contacting Mexican consulates along the border or medical examiners' offices. In Tucson, the Pima County medical examiner's office, which handles most of the state's borderland, is inundated by inquiries from the families of missing migrants. Of the 161 illegal immigrants whose remains it handled last year, more than 20 remain unidentified.

"We're approached by relatives all the time, saying, 'My brother crossed the border two or five or 10 years ago,' " said Bruce Anderson, a forensic anthropologist at the medical examiner's office.

Although the office has begun keeping extensive records, it has yet to match a set of remains with a family searching for missing relatives. Anderson believes that Baker's project could result in such matches. "They're all people, and they all deserve a name," he said.

Baker received an enthusiastic response in her initial contacts with local officials, who are responsible for the disposal of unidentified bodies. They seemed particularly grateful that Baker, who plans to finance her project with research grants, is not proposing to charge counties for the DNA work, which can be expensive in commercial labs.

"The counties would love it -- this is going to make a lot of counties feel like a load has been taken off their backs," said Dorothy Weddle, the justice of the peace of Val Verde County in south-central Texas. "They're going to say, 'I thank God for little miracles.' Especially when you mention money, they're going to sit up and listen."

As a justice of the peace, Weddle is responsible for identifying corpses and determining the cause of death. Too often, she said, the task is all but impossible.

"Usually a body, decayed or just bones, is found by some rancher," she said. "Most of the time, there's no ID with them, and if they do have ID, then more than likely it's not theirs. A lot of time, there's nothing we can do. It's very disappointing because you know that somewhere there's a family that's wanting to know where their relative is."

Baker, who has begun seeking private research funds, reckons she needs $150,000 to get her project rolling. She acknowledges that matching families with their missing relatives would be slow going at first. Success, she said, might mean just one match in the first year or two.

But she has resources at her disposal, including the laboratory facilities at Baylor and a host of undergraduates eager to help with exhumations, possibly beginning as early as this summer.

Ultimately, she said, the project is about the Mexican boy whose remains are laid out in the Baylor laboratory and others like him.

"If we can ID the boy," Baylor said, "we'd like to name the program after him."

Special correspondent Karin Brulliard contributed to this report.

Lori Baker, shown with Jesse Cardenas, caretaker of the San Felipe Cemetery in Del Rio, Tex., hopes to match Mexican migrants buried anonymously with the DNA of their families.