Two brothers jailed in connection with the shooting deaths of a gay couple earlier this month in Northern California are being investigated for their role in arsons at three Sacramento area synagogues and possible connections to nationwide racist groups, authorities said today.

Federal and Shasta County law enforcement officials said a search of the Redding area homes of Benjamin Matthew Williams, 31, and James Tyler Williams, 29, turned up a notebook linking the brothers to the June synagogue fires and produced racist, antisemitic propaganda, including materials related to the World Church of the Creator.

Benjamin Nathaniel Smith, who went on a shooting rampage in Illinois and Indiana last weekend, was an adherent of that white supremacist group based in East Peoria, Ill. Police said Smith targeted blacks, Asians and Jews, killing two men and wounding nine people before committing suicide during a police chase on the Fourth of July.

Shasta County sheriff's department Capt. Ron Richardson said authorities tracked down the Williams brothers after they tried to pick up merchandise they had ordered with the credit card of one of the shooting victims. Gary Matson, 50, and Winfield Scott Mowder, 40, were found slain in their home July 1 in Happy Valley, southwest of Redding.

When the Williamses were arrested Wednesday in Yuba City, Richardson said, they were carrying in their car an arsenal that included two assault rifles, two handguns, a shotgun and substantial ammunition. But he said the men had no prior record in the county.

"They look like a couple of all-American boys," Richardson said. "They don't have any weird tattoos. They're not skinheads."

Federal authorities are pursuing not only the connection to the synagogue arsons, but also whether the brothers may be associated with hate groups. The World Church of the Creator, for example, has 10 chapters in California, and parts of this Sacramento River valley have long been known as hubs both for a few loosely organized anti-government militias and for white supremacist groups. Local police, however, stressed today that there have been no hate crimes in the area for some time.

The California arrests come only days after Smith's rampage and at a time of rising national concern over attacks against minorities. Unrelated to the recent incidents, the White House will hold a summit Monday with civil rights leaders to work toward strengthening the federal government's ability to investigate and prosecute crimes based on a victim's race, sex or sexual orientation.

The brothers were arraigned Friday on charges of receiving stolen property that was linked to the slain gay couple. Richardson said today that authorities expected to charge the men with murder next week. They are being held on bail of $150,000 each.

The Williams brothers, who each go by their middle names, are relative newcomers in Redding. Police said today that their family moved here from Idaho a few years ago, but some neighbors and a former employer of one of the men said that at times they have expressed extreme political views.

Ed Smith, who runs a plant nursery where one of the brothers had worked, would not elaborate on their beliefs but remembered telling Matt Williams not to rant to customers.

"He definitely had strong opinions on some things," Smith said.

The Williams brothers have run a small landscaping business in the area for the past two years, and that is how they apparently became acquainted with Matson, a horticulturist who helped found the Redding Arboretum, and Mowder, who worked in the nursery of a hardware store. One of the Williams brothers bought and sold plants at a farmer's market that Matson founded.

Police here say that neither of the brothers has a criminal record locally. According to local media reports, Matthew Williams is a Navy veteran. The two men, who some here say are both deeply religious, apparently lived in recent years with their parents just outside Redding in an affluent and well-tended suburban community. But they recently moved into a ramshackle house back in town.

A neighbor of their parents said today that both men had not previously aroused suspicion in the community and seemed clean-cut.

"We've never had any trouble with them in this area before," said Glenn Tishue.

Today, federal and local authorities confirmed the connection between the Williams brothers and the arsons that reportedly caused more than $1 million in damage at the three synagogues--Congregation B'nai Israel in downtown Sacramento, Congregation Beth Shalom in Carmichael and Knesset Israel Torah Center in northeastern Sacramento County. The fires erupted within 30 minutes of one another early June 18, and at one of the synagogues police found a leaflet blaming the "International Jew World Order" for the war in Kosovo.

Among the items discovered in the brothers' homes--one in Redding and their parents house in nearby Palo Cedro--was a notebook listing the names of people connected to the synagogues.

"Most of the names were those of individuals associated with the three burned synagogues," said Nick Rossi, FBI spokesman in Sacramento, adding that investigators do not know why the men collected the names on the list. The FBI also said there was no immediate evidence of any plan by the brothers to commit violent acts against specific people.

Other federal officials familiar with the investigation said authorities are trying to determine whether the Williams brothers are linked with other people engaged in criminal activities or connected to larger organizations. While agents found materials from the World Church of the Creator, which made headlines recently because of Smith's involvement in it, one federal source stressed that the brothers had a vast variety of materials from several hate groups.

World Church of the Creator members have been connected to numerous hate crimes in recent years, including the 1993 bombing of an NAACP office in Tacoma, Wash., the 1997 beating of a black man and his teenage son outside a theater in Sunrise, Fla., and last year's beating of a Jewish video store owner in Hollywood, Fla.

Staff writers Joan Biskupic and Roberto Suro in Washington and special correspondent Cassandra Stern in Los Angeles contributed to this report.

CAPTION: Benjamin Matthew Williams looks around courtroom as James Tyler Williams listens to the judge during bail hearing in Shasta County Superior Court on Friday.