Brandishing insults and a gun, Roy Warden routinely threatens Latinos with death. Some observers fear the worst. (Jackie Mercandetti)

TUCSON, Ariz. -- Sunday services were under way inside St. Augustine's Cathedral. Outside, the summer air was still and quiet except for a few birds chirping in a courtyard near the entrance. But the serenity was doomed. A car pulled up, and a graying, bespectacled man carrying a handgun and a loudspeaker got out, two cameramen in tow.

Working fast, he positioned a collection of lawn chairs on the public sidewalk in front of the Catholic cathedral, then encircled the lawn chairs with what appeared to be a series of pink jump ropes and planted two American flags. With the bravado of a professional wrestler, he then stepped into the roped-off ring he'd constructed, threw down a Mexican flag, and ceremoniously stomped on it, grinding his heel for the cameras.

Then he turned on the loudspeaker and addressed the worshippers inside St. Augustine's.

"You people don't seem to understand forbidden territory, whether it's a child's anus or the American border! You just want to push on in, don't you?" he screamed, his face flushed with anger. "We are going to be driving you back to Mexico real goddamn soon!" Spit flew from his mouth. "Get used to it! My name is Roy Warden, and I burn Mexican flags!"

Defensive Perimeters
With a fanny pack loaded with water bottles strapped to his belly, a Glock 9mm on his hip, and a bullhorn to amplify his outrage, Roy Warden, 59, emerged this spring as one of the country's most controversial, volatile, and, many believe, dangerous characters of the anti-immigration movement. Along with occasional sidekicks Russ Dove, a former militia leader and convicted car thief, and Laine Lawless, the founder of the group Border Guardians who earlier this year urged neo-Nazis to terrorize Hispanics, Warden has burned and trampled Mexican flags in public, nearly started at least one riot, regularly wreaked havoc on Tucson City Council proceedings, and E-mailed a death threat to a prominent local public defender. Without regular followers or even a named group behind him, Warden is a one-man band of immigrant-bashing hate, a man so untamed that other anti-immigration activists shun him as an embarrassment.

Warden's tactics are over the top even for southern Arizona, a longtime hotbed of anti-immigration extremism. A typical Warden event has him standing within a roped-off "defensive perimeter" on a public sidewalk or in a city park, threatening to shoot anyone who crosses his line, then trampling and burning a Mexican flag while shouting insults through a bullhorn. In one recent instance he called Mexican immigrants "cowards and traitors who have abandoned the dream of Zapata and Marcos to feed like dogs on the table scraps of gringos."

Tucson is 70 miles from the border. Thirty-five percent of the city's half million residents are of Mexican descent. More often than not, Warden draws an angry crowd whose members he then bullies and taunts with carefully worded death threats such as, "If you try to inflict deadly harm upon me, I'll fucking blow you away!"

Warden may come off like a raving lunatic, but he is well versed in free-speech and self-defense laws, and he exercises his rights to the limit. As he explained to the Tucson City Council last May: "I am empowered to use deadly force to protect my own life. Now this is what it's gonna mean. It's gonna mean I'm gonna have a perimeter, I'm gonna speak through a loudspeaker down in the barrio, any place I want, and if people try to kill me, try to overrun my position, I will discharge a shotgun in their face!"