Do-It-Yourself Border Patrol

Less than 10 miles from the Mexican border, a vacant lot in Sierra Vista, Ariz., looks like a trash dump. Between the chaparral and scrub oaks are backpacks, sweatshirts, jeans, sneakers, used toilet paper and water bottles filled with urine. Chris Simcox, a small-town newspaper owner, flips through a book he picked out of the refuse titled Aprenda Ingles sin Maestro (Learn English Without a Teacher), shakes his head and says, "Welcome to the invasion."

More than 500,000 illegal aliens were caught last year in southern Arizona alone, accounting for 52% of all undocumented migrants detained in the U.S. in 2004. But Simcox, fed up with what he sees as government inaction in the face of lawlessness and a threat to national security, plans to do something about it. As head of a two-year-old group called the Civil Homeland Defense Corps, he is spearheading a new Minuteman Project that will place volunteers at quarter-mile intervals to watch a busy 50-mile stretch of border for the entire month of April. The goal, he says, is not to confront migrants but to monitor and report their locations to the U.S. Border Patrol.

The movement has aroused fears of vigilantism. Mexican President Vicente Fox has called groups like Simcox's "immigrant hunters," and President Bush said last week, "I'm against vigilantes." Jennifer Allen of the Border Action Network says she is preparing a human-rights complaint against the U.S. government for "failing to prosecute vigilante groups." Local officials in Arizona are nervous about hundreds of Minuteman volunteers coming from out of state, and Michael Nicely, head of the Border Patrol's Tucson sector, says the Minuteman Project will "hamper border safety."

Simcox bristles at the term vigilante, saying that his group is not detaining anyone but only fulfilling the President's post--Sept. 11 request that all Americans remain vigilant--and, in the process, providing a release valve for popular outrage. U.S. Customs and Border Protection officials, meanwhile, tell TIME they will announce a "significant increase in resources" this week to address the influx of illegal immigrants still crossing by land in Arizona. --By Brian Bennett