Far from any sacred ground, the skulls of ancient Indians sit stacked inside an old, wooden vault.

They were pilfered from their final resting places, their valuables stolen by looters looking for a big payday. After the investigations, they ended up here.

It is a quandary for authorities and tribes: Authorities want to return the remains, but tribes are sometimes reluctant to accept them. Indians never intended to rebury their dead, never contemplated such a thing. There are no rituals for it, no way of knowing who these people were or where they came from. Often, there is nowhere to bury them.

And so they stay in a government evidence vault, or sometimes in cardboard boxes tucked in a reservation's warehouse.

It is, Indians say, a journey interrupted.

On the northwest side of Albuquerque, in a dusty, desert area most people would easily pass by, criminal investigator John Fryar cautiously stepped between deep holes that dot what used to be an Indian village.

Fryar knows just what to look for -- mounds of dirt, changes in vegetation, surface artifacts strewn about the area. Looters have been here many times. Even though it was years ago, they left behind a scarred land.

A national criminal investigator with the Bureau of Indian Affairs, Fryar is the government's only full-time special agent enforcing the 1979 Archaeological Resources Protection Act, which makes it illegal to remove remains or artifacts more than a century old from Indian and federal land. Most states have similar laws for their lands.

For decades, picking up a few pieces of Indian pottery or arrowheads poking out of the dirt did not get much attention. "Pot hunting" was even a family activity, especially in the wide-open space of the West. Many people simply stumbled upon pots or baskets, stuffed the pieces in their pockets, took them home and put them on a shelf. It was accepted.

But pot hunting has changed immensely. Now, Fryar sees fewer amateur pot hunters but a huge black market run by professional looters. They act like archaeologists gone berserk, researching Indian sites, then renting backhoes and trenchers, and ripping through burial grounds with precision and purpose -- to make big money.

They sell headdresses, arrowheads, grinding stones, remains and prized pottery that can fetch thousands, even millions of dollars in backroom deals at trading posts and on the Internet auction site eBay.

Fryar rattled off his cases: skulls sitting on bookshelves; remains displayed in a glass coffee table; a man in Hawaii who had 30 sets of Indian remains stored in his closet; another who bragged about taking toys out of the skeletal hands of long-dead babies.

He investigates 40 to 50 looting cases all over the country each year, but he is certain there are hundreds more he never hears about.

Only about half of Fryar's cases are prosecuted, because of a lack of evidence or lack of interest by authorities.

"It's very frustrating. It seems that there's so many other things on everybody's plate -- homeland security, they've got immigration problems. These, a lot of times, take a back seat," he said.

In the past six years, he has recovered 10 Indian skulls he hoped to return to tribes for reburial under the Native American Graves Protection and Repatriation Act. Instead, they sit unclaimed in stacked cardboard boxes in the evidence vault of a Santa Fe government office.

Like scavengers on a treasure hunt, looters rummage through grave sites with no regard for the dead. Sometimes they leave bones behind as soon as they find the valuable pot buried with the body.

For some tribes, the pots were buried with the dead in the belief that they would release spirits to the next world. They are the most sacred pottery to Indians, and for the black market, the most profitable. Bowls made by the Mimbres Indians, who lived in southwestern New Mexico more than a thousand years ago, can sell for as much as $150,000.

Looters know where to look. By studying an area and knowing where the room blocks of a village were, they can easily pinpoint the pots because they know Indians were buried under the rooms.

Looters have struck a burial site of the San Carlos Apache tribe in Arizona repeatedly for almost two years. Shovels, other tools, pottery pieces and bones litter the area now filled with large pits.

Tribal archaeologist Vernelda Grant suspects the same people are responsible for the looting, but with 1.5 million acres to patrol, the tribe has yet to catch anyone.

It is a perpetual battle for many tribes because they have few resources to catch looters. Sometimes, tribal members even assist the criminals in exchange for money. Just weeks ago, Grant saw one of the tribe's ancient headdresses for sale on eBay.

Soon, Apaches will have to decide what to do with the scattered bones and broken pottery at the burial site.

Many tribes struggle with the same dilemma. They never planned on putting their ancestors back into the ground. Once buried, the dead are supposed to begin their journey to the next world.

The notion of that journey being interrupted, requiring a second beginning through reburial, is offensive to the culture.

"Now they're going to have to find a way to get that soul from that body back on its journey," Fryar said. "Sometimes I don't know if you can even do that. They don't know what process it's gone through. Was it used for satanic purposes? Was it used for something that was not proper?"

Some tribes do not want the remains back because they fear being exposed to an ancestor who was evil or had a disease. They do not want evil returning to them.

"They don't know if that person was a witch or not," New Mexico state archaeologist Glenna Dean said. "It's one of the more surprising and sad aspects of trying to return the dead to their families."

There usually is no process for reburying looted remains or artifacts. For tribes such as the Navajo, it is taboo to handle remains. It is believed that doing so would bring illness to tribal members. Indians hope to rebury remains as close as possible to where they were found, but the location is not always known.

"Once we put them with Mother Earth, there's nothing else we can do," said Arlen Quetawki, governor of the Zuni Pueblo in New Mexico. "Unfortunately, now you're left with human remains. It's something that tribes have to deal with. What do we do with them? Where did they get them?"

Only a few Navajo Indians know they are there -- 10 sets of remains packed in cardboard boxes in a locked room of a warehouse -- but they rarely speak of them. They have been here for years, awaiting reburial.

Now the tribe plans to create a burial ground specifically for remains that were looted, excavated during construction or repatriated from a museum. The tribe will ask non-Navajos to handle the burials.

"This is something that we're working on right now," said Ron Maldonado, program manager for the tribe's Historic Preservation Department. "The remains are going to go back. That way they're no longer in storage."

Other tribes are also considering separate burial sites but will have to choose areas they hope will not be looted again.

Dean said having a state cemetery for unclaimed remains, Indian and non-Indian, is something the state would like to pursue. Several states already have such cemeteries. Quetawki said it has been suggested that the 19 New Mexico pueblos select a site to bury all unclaimed remains, but there is no formal plan.

"It's almost a conflict for us," said Grant of the Apache tribe. "It's one of our responsibilities. It's almost creating a whole new ceremony to rebury a second time. That's what we're faced with. It's such an awkward thing."

The Arizona State Museum has about 6,000 sets of remains in storage, but most were exhumed during construction projects. There are a few sets of looted remains waiting to be claimed.

"This wasn't on the agenda. . . . We're attempting to return one historic Apache person, but the tribes themselves can't handle remains," said John Madsen, museum repatriation coordinator.

Reburial is not just a logistical problem but also a spiritual one.

Indians wonder who the ancestors were. Were they good or bad people? What ceremonial artifacts were buried with them? What happened to those? Will bad energy come to Indians who accept the remains?

It is more than just damage to graves, but a disruption of the cycle Indians live within.

Dosela surveys a Salado burial site east of Phoenix. The 1979 Archaeological Resources Protection Act makes it illegal to remove remains or artifacts more than a century old.Pottery shards and flint were found at a pueblo outside Albuquerque. Looters claim items worth the most on the black market: headdresses, arrowheads, grinding stones.On the San Carlos reservation, from left, archaeologist Garry Cantley and tribal rangers Jerrel Wilson and Perry Dosela examine a burial site. Dirt mounds indicate a disturbance.