Rare because he and his family were Muslims in this quiet rural subdivision where the denominations generally run from Baptist to Presbyterian. But also rare for his intensity.

“How many Christians you see standing in the yard praying five times a day?” asked Jeremy Kuhn, 20, who lives across the street. “They just believed more than anyone else.”

But to the disbelief of Mr. Kuhn, the federal authorities say Mr. Boyd and two of his sons took their convictions beyond religious faith and into terrorism. They were among seven men charged on Monday with supporting violent jihad movements in countries including Israel, Jordan, Kosovo and Pakistan. An eighth man was still being sought, said a spokeswoman for federal prosecutors in Raleigh, about 20 miles north of here.

The men are charged with stockpiling automatic weapons and traveling abroad numerous times to participate in jihadist movements. There is no indication in the indictment that they were planning attacks in the United States, though prosecutors said they had practiced military tactics this summer in a rural county close to Virginia.

Their plans apparently involved a suicide attack, according to an e-mail message Mr. Boyd sent in 2008 to another defendant, Hysen Sherifi, about dying as a martyr.

Besides Mr. Boyd, who is 39, the indictment names his sons Zakariya, 20, and Dylan, 22; Anes Subasic, 33; Mohammad Omar Aly Hassan, 22; Ziyad Yaghi, 21; and Mr. Sherifi, 24. All are American citizens except Mr. Sherifi, who is from Kosovo and has legal residence in the United States. Detention hearings for the men are set for Thursday.

Mr. Boyd, the son of a Marine, is a convert to Islam, and received training from Islamic radicals in Pakistan and Afghanistan, the indictment said.

Prosecutors said much of the activity took place over the last three years, citing coded conversations, exchanges of cash, numerous gun purchases and a Kalashnikov demonstration in Mr. Boyd’s living room.

Mr. Boyd, the central figure in the indictment, is also charged with lying to federal agents in 2007 about his reasons for a trip to Israel. According to the indictment, he and several other defendants had intended to join violent jihadists in the Palestinian territories, though the trip was ultimately unsuccessful.

It was the second trip to Israel mentioned in the indictment. Mr. Boyd is said to have taken his son Dylan to Gaza meet jihadists in March 2006, though that, too, was apparently unsuccessful.

Highlighted in the indictment, but not part of the charges, was a period the authorities say Mr. Boyd spent with his brother in Afghanistan and Pakistan from 1989 to 1992, training with and supporting fighters who were trying to overthrow the Soviet-backed government in Kabul. They were in the news at the time, when the Pakistani government charged them with bank robbery and sentenced them to lose their right hands and left feet. (The convictions were overturned by the Pakistani Supreme Court at the urging of the State Department.)

Federal officials in Washington said that the men charged on Monday were not seen as serious terrorist threats to the United States or American interests abroad, and that there were no indications of ties to Al Qaeda or other militant groups. But the officials said there was concern that they were amassing a sizable number of automatic weapons, given Mr. Boyd’s record as a foreign fighter.

“What essentially this is about is a guy with foreign fighter experience,” said one law enforcement official, who spoke on condition of anonymity because of the pending prosecution, “who comes back to the U.S. from the conflict zone with street cred and a network of contacts overseas, intending to recruit others who were on the fence.”

Mr. Boyd’s wife, Sabrina, cited that same period in defense of her husband. “He was there fighting against the Soviets in a war that had the full backing of the U.S. government,” Ms. Boyd said through a spokeswoman, Khalilah Sabra of the American Muslim Society Freedom Foundation, an advocacy group.

Ms. Boyd is also an American, and, according to a 1991 Washington Post report, the couple were high school sweethearts in Northern Virginia. A neighbor said the Boyds looked for other churches before settling on Islam. The Post profile said Mr. Boyd’s stepfather was a Muslim.

“The charges have not been substantiated,” Ms. Boyd said. “We are an ordinary family, and we have the right to justice, and we believe justice will prevail. We are decent people who care about other human beings.”

Neighbors were startled, even angered by the arrests, which they learned about when federal agents, some carrying assault weapons, swarmed over the lawn of the Boyds’ house.

The house, with a Ford Bronco in the driveway and a swimming pool in the back, looks like any other in the quiet subdivision, and neighbors said the Boyds were generally no different than anyone else, other than being nicer than average. Mr. Boyd ran a company installing drywall, for which his two older sons often worked. The Boyds had two younger sons, one of whom was killed in a car accident two years ago, and a daughter.

Prosecutors said Mr. Boyd had stopped attending mosques this year because of “ideological differences” and had begun having Friday prayer services at home.

The Boyds had the usual interactions with the neighbors — tool swapping, rides to school — and other than a day when the house was egged, which neighbors attributed to their religion, their faith did not seem to be an issue.

“We never really had a problem with it,” said Anthony Perfetto, 15, who used to have after-school snacks at the Boyd home. “All they’d say about it was like they had to go pray, and that’s about it.”

All of which has left neighbors shaking their heads and repeating that there must have been some kind of mistake.

“I don’t believe any of this,” Mr. Kuhn said. “And it’s going to take a whole lot of evidence to convince me otherwise.”