A morning with Smith's team shows how difficult it is to find the absconders, part of a rising tide of illegal immigration. The fugitive squads capture 35 people a day across the country, on average. But each day, another 70 immigrants are ordered deported and fail to comply, officials say. So the absconder population grows ever larger. "We're still in the midst of the battle in terms of control," acknowledged Victor Cerda, a top official at the department's Immigration and Customs Enforcement. The immigrant sought by Smith's team was typical of the problem. Etienne Kabert, from the Ivory Coast, had applied for political asylum, officials said. He was turned down, and an immigration appeals court sent him a letter in July 2003 ordering him to leave the country. He never did.

Like Kabert, most immigrants aren't jailed while their cases are heard. About one-third vanish before their cases are decided, Cerda said. Of the remainder, about 85 percent of those who get deportation notices don't show up for final processing, he said. For years, the absconders knew that immigration agents were too busy to turn up at their doors. That is now changing, as was evident as Smith's team cruised down the road on a recent Tuesday. Under a moonlit sky, Smith watched his officers file into the Hamilton Manor Apartments. A light snapped on in an upstairs window. But it was Kabert's roommate. The man they sought was working an overnight shift, the officers relayed to their supervisor. Smith gazed impassively at the building. "We'll be back," he declared.

The absconder program began as the immigration system was facing a volley of criticism after the Sept. 11 attacks. What better place to start fixing the system, officials reasoned, than the absconders? Unlike most of the country's 8 million or more illegal immigrants, the absconders were known to the government -- because they'd been detained briefly on immigration charges or had applied for legal status. And they'd had their day in court. At the top of the list were 6,000 absconders from Muslim and Middle Eastern countries, officials announced. But by early 2003, authorities had resolved only 38 percent of those cases, either by detaining the immigrants or by confirming that they had left the country or gotten legal status, according to the 9/11 Commission. In a report on terrorist travel, the commission concluded: "It is very difficult to find alien absconders without extraordinary effort or pure luck."

The reasons for the difficulty were clear as Smith's team glided through the slumbering neighborhoods of Hyattsville. The officers had three targets in addition to Kabert. They had tried to pinpoint the immigrants by scouring real estate and other records. But the absconders left little paper trail. At 6:20 a.m., the fugitive squad pulled up in front of a tiny house with a birthday balloon bobbing from the mailbox. The target: a British immigrant ordered deported a decade ago. Like up to 20 percent of the absconders, he had a criminal record, for marijuana distribution and child abuse, officials said. But the couple answering the door said the man had moved three months earlier. The team moved on to its next target, a Nigerian believed to be living in an apartment tower called the Seville. Minutes after the agents disappeared into the elevator, Smith's radio crackled. "There's no occupant. They just moved in September." Smith chewed his gum and looked into the darkness. "Couple days late. This is the frustrating part."

Then it was on to brick rambler trimmed with white icicle lights. The officers were seeking a Guatemalan man. They found a Salvadoran family. "Green cards galore," said an agent, emerging from the home. Smith sighed. "Boy, this makes for a long day." The Guatemalan had moved years ago.

The search for the absconders wasn't supposed to be this difficult. When the program was announced in December 2001, officials said they would put the absconders' names into FBI's National Crime Information Center database. That would allow local and state police to identify whether people they stopped for routine infractions were on the list. But after three years, only 38,521 names are in the database -- about 10 percent of the absconders -- said Russ Knocke, a spokesman for Immigration and Customs Enforcement, or ICE. "It's a workload issue," he explained.

Dozens of federal lawmakers have backed measures to enlist local and state police in the effort to detain illegal immigrants, including absconders. But the idea has been fiercely opposed by immigrant advocates and some politicians, who believe it would shatter the trust between police and immigrant communities, making it harder to solve crimes. Some also worry it could foster ethnic profiling. For all their frustrations, the fugitive teams have made progress. In the first seven months of fiscal 2004, they apprehended 7,239 absconders, twice as many as in the same period a year earlier, according to ICE statistics. The agency is now drawing up plans for 30 more teams. But budget problems have bedeviled ICE, and Knocke said it wasn't clear if all 30 teams would be fielded by the end of 2005. Even with the new teams, it will be hard to track down all the absconders. But the squads at least are starting to change a culture of impunity, officials say. As recently as the 1980s, many immigrants showed up for deportation processing, former officials said. But then a surge of illegal immigration overwhelmed the ability of agents to keep up. "People feel they can get away with running ... because the immigration law isn't enforced anywhere else," said Mark Krikorian, executive director of the Center for Immigration Studies, which seeks more limits on newcomers.

The solution goes beyond adding fugitive teams, officials say. Cerda, an intense young Mexican American lawyer who heads the detention program at ICE, said the government has to keep people from becoming absconders in the first place. Cerda is now overseeing several pilot programs to better track immigrants through their court proceedings. Some immigrants are required to wear electronic ankle bracelets; others must call in periodically. Locking up everyone facing immigration charges isn't feasible because of a lack of detention beds, he said, but another solution must be found. "The honor system has failed," he said.

By 7:50 a.m., Smith's team had returned to Kabert's apartment building. As the agents went inside, Smith absentmindedly rapped his knuckles on the steering wheel of his Ford Expedition. Traffic whooshed by. Smith stared silently out the window. Twenty minutes passed.