El Paso, Texas ? For all the tough talk out of Washington on immigration, illegal immigrants caught along the Mexican border have almost no reason to fear they will be prosecuted.

Ninety-eight percent of those arrested between Oct. 1, 2000, and Sept. 30, 2005, were never prosecuted for illegally entering the country, according to an Associated Press analysis of federal data. Nearly 5.3 million immigrants were simply escorted back across the Rio Grande and turned loose.

The number of immigrants prosecuted annually tripled during that five-year period, to 30,848 in fiscal year 2005, the most recent figures available. But that still represented less than 3 percent of the 1.17 million people arrested that year. The prosecution rate was just less than 1 percent in 2001.

The likelihood of an illegal immigrant being prosecuted is “to me, practically zero,” said Kathleen Walker, president-elect of the American Immigration Lawyers Association.

Federal prosecutors along the nation’s southern border have come under pressure from politicians and from top officials in the Justice Department to pursue more cases against illegal immigrants.

But few politicians are suggesting the government prosecute everyone caught slipping across the border. With about 1 million immigrants stopped each year, that would overwhelm the nation’s prisons, break the Justice Department’s budget and paralyze the courts, immigration experts say.

The Justice Department says it has higher priorities and too few resources to go after every illegal immigrant. The department says it pursues more selective strategies, such as going after immigrant smugglers and those with criminal records.

Under federal law, illegally entering the country is a misdemeanor punishable by a fine and up to six months in prison for a first time. A second offense carries up to two years. If an immigrant has been prosecuted and deported and then sneaks back into the country, he can be charged with a felony punishable by up to two years behind bars. Those with criminal records can get 10 to 20 years.

The federal figures on arrests and prosecutions were collected and provided to the AP by the Transactional Records Access Clearinghouse at Syracuse University in New York.

Justice Department spokes-man Dean Boyd said in a statement that 30 federal prosecutors have been added to the border to handle the rising number of immigration and border drug cases and noted that securing more prosecutions would require hiring more judges and public defenders and building more courtrooms and jails.