TRINIDAD, Texas – Gary Thomas will never forget the letter he received in early 2000. It was from John Joe Gray, a suspect in a felony assault case, offering a not-so-subtle warning to the area's chief criminal investigator: He had no intention of answering charges that he had attacked a state trooper.

"What he said was this: 'If y'all come to get me, bring body bags,' " said Thomas, now a local justice of the peace.

Thomas remembers the message clearly, not because of its unvarnished threat, but because — after 12 years — Gray, who doesn't acknowledge the authority of any government, continues to dare police to come and get him.

Sequestered on a 50-acre, wooded compound in East Texas since jumping bail more than a decade ago, Gray and his clan have effectively outlasted the administrations of four local sheriffs, all of whom have decided that John Joe's arrest is not worth the risk of a violent confrontation.

"The risk of loss of life on both ends is far too great," said Anderson County District Attorney Doug Lowe, who first sought to prosecute Gray for the alleged Christmas Eve 1999 assault of Texas Trooper Jim Cleland. "I believed it then; I still feel that way."

John Joe Gray: Doesn’t acknowledge the authority of any government Anderson County (Texas) Sheriff's Office

The stalemate, perhaps the longest-running standoff in the U.S. between law enforcement and a fugitive living in plain sight, is also emblematic of what the FBI believes is a troubling re-emergence of an anti-government movement that vaulted to notoriety in 1995. Then, one of its disaffected sympathizers, Timothy McVeigh— angered by the government's botched 1993 raid of the Branch Davidian compound in Waco, Texas — detonated a truck bomb outside the Oklahoma City federal building, killing 168 people in what was at the time the deadliest terrorist attack on U.S. soil.

In the past three years, there has been growing concern over activities of so-called "sovereign citizens," who like the Grays and many of their anti-government predecessors "claim to exist beyond the realm of government authority," according to a January FBI bulletin to state and local law enforcement officials warning of the potential for violence.

The sovereign movement, estimated by the Southern Poverty Law Center to number 100,000 ardent followers and about 200,000 sympathizers across the country, is rooted in an ideology that rejects government authority at its most basic levels, from its power to tax to the enforcement of criminal laws, including common traffic regulations. The law center, which tracks extremist groups in the USA, based its estimates partly on its reviews of tax disputes and court documents involving people who do not recognize government authority.

Although the FBI does not track sovereigns by number, the bureau does not dispute the law center's estimates, which have swelled dramatically within a national anti-government network of related "patriot" and "militia'' groups. Since 2008, the number of groups surged from 149 to 1,274 in 2011, the law center reported this month.

The rapid growth, according to the law center, has been fueled by a collision of factors, from the troubles related to the struggling economy and foreclosure crisis to the election of President Obama, the nation's first black president. Obama's election prompted a "backlash" from extremist groups who were further angered by decisions to provide government assistance to Wall Street banks and automakers, the law center found.

Stuart McArthur, deputy assistant director of the FBI's Counterterrorism Division, said the sovereigns have become more active in seeking retaliation against government officials by filing fraudulent lawsuits and liens, seeking billions of dollars in judgments. The actions often follow arrests, evictions, court rulings and other interactions with authorities.

At its most extreme, McArthur said, sovereigns have been linked to threats of violence and the murders of six police officers since 2002, including the slayings of officers Brandon Paudert and Bill Evans in West Memphis, Ark., in 2010.

Militia groups swelling The anti-government patriot/militia movement, marked by a deep distrust of the government, has grown dramatically in the past four years. Source: The Southern Poverty Law Center

"There are people at war with this country who are not international terrorists," said Robert Paudert, the former chief of the West Memphis Police Department and the father of one of the slain officers. "I had never heard of the sovereign citizen movement before May 20, 2010 (the day of his son's murder). But these are people who are willing to kill or be killed for their beliefs."

At Gray's property line

At the end of a rutted, dirt-gravel road, about 70 miles southeast of Dallas, sits John Joe Gray.

It doesn't take long to learn that Gray and his family, after more than 12 years of living in isolation without electricity and modern plumbing, have no intention of surrendering to local authorities or engaging in much discussion about their plight.

A heavily armed patrol of three men — each carrying holstered handguns, knives and rifles — meets visitors one late February afternoon at the family's property line, a fence line festooned with weathered placards bearing anti-government slogans.

"When people fear the government, there is tyranny. When government fears the people, there is freedom," reads one. Another: "Vaccinations equal Annihilation."

Although the three confirm to USA TODAY during a recent visit that they are members of the Gray family, they refuse to provide their full names. The oldest — a bearded man with a mane of long, wiry hair who most resembles Gray's 12-year-old booking photo — said the family is not interested in discussing why they continue to defy authorities. Nor are they inclined to say how long they can hold out.

"We're doing all right," the older man said curtly, adding that the family tends a sizable garden on the property that yields much of their food. A herd of goats, fish from the adjacent Trinity River and wild game help fill their pantry.

For the duration of the brief exchange, a stilted conversation at the fence line, the older bearded man does much of the talking as the others look on, their weapons hanging from worn gun belts and shoulder slings. The weapons, he said, are necessary to keep "trespassers" off their land, suggesting that would include unwelcome visits from law enforcement. He is most adamant, though, in his refusal to discuss the circumstances that have resulted in his unusual standoff with local law enforcement.

"Everybody knows the government controls the media," he said.

Gray fled here, according to Thomas, Lowe and Henderson County Sheriff Ray Nutt, after the now-63-year-old man was released on bond in connection with the 1999 alleged assault on Trooper Cleland.

During a routine traffic stop in neighboring Anderson County, Thomas said Cleland saw a .357-caliber handgun in the car and reached for it, sparking a struggle with Gray that spilled onto the roadway. During the struggle, Thomas said, Gray "bit a plug" of flesh out of Cleland's arm.

A search of the vehicle produced some rambling anti-government writings, including references to setting off a bomb on a highway overpass near Dallas.

Gray denied any part in a bomb plot; he was indicted, instead, for the alleged assault. Gray was released on bond, partly on his promise that he would have no access to weapons while free awaiting a hearing. Gray never returned to answer the charge.

Nutt, the fourth sheriff to hold office in the county where Gray is holed up, said he is comfortable not forcing Gray's hand. That decision, he said, is largely informed by the consequences of the federal raid on a Waco compound housing the Branch Davidian religious sect and its leader, David Koresh. Federal agents stormed the property in search of weapons in February 1993, leading to a 51-day standoff, ending in a conflagration that left 80 dead and inspired McVeigh. The specter of that tragedy still looms large here, where the Gray property lies about 80 miles east of Waco.

"I'm reluctant to talk about (the Gray case) much," said Nutt, a former Texas Ranger who was dispatched to Waco at the time. "I just don't want to stir things up."

That's not to say Nutt has ignored the current standoff. A thick file holds a pile of documents related to the Grays. It's believed that seven children live among the 15 people on the property, the sheriff said. Nutt won't discuss any law enforcement surveillance of the compound, although they know sympathizers occasionally drop off food and supplies. The sheriff also believes the family has access to a ham radio, maybe a generator.

The sheriff is not comfortable discussing much more, except to emphasize the strong belief that his department would not have the "firepower" to sustain a prolonged siege to forcibly remove Gray.

"Some of our officers would be killed, mostly likely," he said.

No taxation

Mark Potok, editor of the Southern Poverty Law Center's Intelligence Report, which has closely examined the Gray case, said the family adheres to sovereign beliefs, an ideology that is attracting an increasing number of followers in the U.S.

The sovereigns are regarded as a subset of the patriot groups and share much of the same ideology, including a rejection of the government's taxing authority. The Grays, according to local court records, owe nearly $20,000 in back property taxes. Citing the same fears expressed by law enforcement officials, the county has stopped attempts at collection.

"This is a widespread ideology," the FBI's McArthur said.

Potok and other analysts believe the financial crisis, triggered partly by the collapse of the housing market, is chiefly responsible for the movement's expansion.

This notion is based on a flurry of federal prosecutions against so-called "tax defiers," suspects in debt elimination schemes and others who have sought to enrich themselves or retaliate against local government officials by filing false property liens and lawsuits seeking outrageous monetary judgments.

Last summer, two New York men, Ed Parenteau, 54, and Jeffrey Burfeindt, 48, pleaded guilty in federal court to attaching fraudulent liens against personal and public property, totaling $135 billion. The motive, according to court records: The pair was "displeased" after local police arrested them on simple trespassing charges.

This week, David Stone, 47, and his son, Joshua Stone, 23, both members of the Hutaree militia, pleaded guilty in a Michigan federal court to possessing illegal machine guns, after a judge dismissed more serious charges that they and other militia members had plotted to attack federal government officials.

The danger ahead

In wake of his son's murder, Paudert, the former West Memphis police chief, is now assisting the Justice Department in a national campaign to prepare law enforcement officials for potential violent encounters with sovereign followers.

Had such information been available in 2010, Paudert said his officers might have recognized the looming danger when avowed sovereign Jerry Kane and his son, Joe, presented them with unusual paperwork indicating the vehicle was registered to the "Kingdom of Heaven."

Minutes later, the Kanes opened fire on the officers and sped away, leaving young Paudert's body on a freeway exit ramp and Evans in a nearby ditch. The Kanes were later killed in a confrontation with police.

"I wish I could have done more to prepare them for what they faced that day," Paudert said.