On an ordinary evening in early January, Judge Radhi Hamza al-Radhi shuffles through the tile-and-glass canyons of the Springfield Mall in Northern Virginia. No one notices him. He doesn't exactly look like a wanted man. He is a bespectacled 63-year-old Iraqi with receding white hair, a clipped mustache, a burn scar from childhood on his crooked nose, and distinctive black eyebrows. Smelling faintly of Aramis cologne, he shambles along, searching for something to do. In his tweed coat and brown shoes, he looks more like a college chemistry professor than the hardened crime fighter he was before everything went wrong and he had to run. (View slideshow.)

The judge comes here daily, sometimes twice a day—it's a three-minute walk from his new suburban hideout. He spends the time walking, gazing into the storefronts, observing faces, but mostly he's lost in thought. Occasionally, his eyes flicker up to the mall's second floor, as if he's looking for his enemies. But they are not there.

We stop at a western-wear shop, where he likes a tall, black Stetson hat, and stroll through Target, his favorite store because it has what he needs for his new life and, as he says, "there are so much sales." We stand near a blinking carousel and watch it turn.

After an hour or so, he enters a Brookstone store and falls into a massage chair. As the mechanical nubs knead his back, he recalls the way his life was in Iraq, 6,300 miles away, where he mingled with world leaders and fought the most important battle of his life. "It seems so long ago," he says. "I never thought it would end this way."

Before he fled Iraq, Radhi was the head of Iraq's Commission on Public Integrity, where he policed the country's government and investigated its biggest cases of bribery and financial chicanery. Set up and paid for, in part, by the United States, the agency was Iraq's F.B.I., and Radhi was compared to Eliot Ness, who took down the Chicago Mob in the 1930s. Stuart Bowen, the U.S. special inspector general for Iraq reconstruction, described Radhi as his "most reliable partner...in Iraq," and Chuck Grinnell, a senior C.P.I. adviser, remembers, "He was one of the good guys, one of the few in Iraq."

The judge was appointed to the post by Ambassador Paul Bremer in the summer of 2004, almost a year after the U.S.-led invasion. At the time, Iraq was a free-for-all, with competing gangs and criminals gunning for a seemingly endless flow of reconstruction cash. The prevailing view held that the C.P.I. was vital to the advancement of the near-broke country, a sentiment reflected by President Bush in a 2005 speech to the Council on Foreign Relations. "Listen," he told a crowded ballroom at the Omni Shoreham Hotel in Washington, "the Iraqi people expect money to be spent openly and honestly, and so do the American people." He would tout the C.P.I. again a month later, in a speech to the Veterans of Foreign Wars.

The judge's job was, simply put, to figure out where the money was going. Billions of dollars were being wasted or stolen outright in Iraq, including $8.8 billion that went unaccounted for in 2003 and 2004. Many of Iraq's leaders were either directly participating in the thievery or quietly supporting it through hired guns, who later waged sectarian wars in the streets. Radhi was supposed to track down the criminals, stanch the hemorrhaging of money, and put an end to the corruption that was dubbed the "second insurgency" by Bowen and considered a principal source of funding for the terrorist groups that the U.S. military was trying to crush.