SCRANTON -- The question of whether the old coal-mining city of Hazleton can begin enforcing its laws to evict illegal immigrants is now in the hands of a federal judge.

Lawyers for the city and civil rights groups challenging the ordinances made their closing arguments yesterday after a two-week trial with national implications.

If Hazleton wins the case, its strategy for drumming out illegal immigrants could be duplicated in cities across the country. Defeat for Hazleton could discourage mayors and city councils from trying to fight immigration battles at the local level.

U.S. District Judge James Munley said he would accept additional written arguments from each side until May 5. He will rule on the constitutionality of Hazleton's laws after that.

Witold Walczak, legal director of the American Civil Liberties Union of Pennsylvania, made the final argument for the various individuals and organizations that say Hazleton's laws are unconstitutional.

He said Hazleton and its mayor, Louis Barletta, had turned immigrants into scapegoats, blaming them for everything that ails the city. Even worse, the mayor's campaign against illegal immigrants has made life harder for legal newcomers, many of whom are now feeling the sting of prejudice from those who dislike foreigners, Mr. Walczak said.

Kris Kobach, a Missouri law professor who was personal counsel to former U.S. attorney general John Ashcroft, made Hazleton's final oral argument.

Quoting demographic experts hired by the city, he said Hazleton has 1,500 to 3,500 illegal immigrants. Hazleton administrators estimate the city's population at 31,000, so they contend that as many as 10 percent of its residents are illegal immigrants.

Mr. Kobach said the lawbreakers pay little in taxes but strain city services. "Hazleton is like a boat in danger of sinking. Every illegal alien drags it down."

He cited violent crime, the sudden rise of street gangs, crowded schools and a hospital overrun with illegal immigrants as the reasons behind Hazleton's laws.

One ordinance would require every new renter to provide proof to the city of his citizenship or legal right to be in America. The other Hazleton laws would penalize landlords who rent to illegal immigrants and businesses that hire them.

Hazleton would not punish anyone until it confirmed through the U.S. Department of Homeland Security that it had found an illegal immigrant, Mr. Kobach said.

Mr. Walczak said immigration law is complicated, and must be administered by the federal government to prevent cities like Hazleton from violating the rights of innocent people.

He accused Mr. Barletta, a Republican, of exaggerating crime statistics and trying to pin the blame for Hazleton's social problems on newcomers, most of whom are from Mexico, Colombia and the Dominican Republic.

Both the mayor and his detractors say Hazleton's population has exploded in the last six years. But in that time, Mr. Walczak said, crime rates in Hazleton have declined.

About 430 violent crimes were committed in the city during that stretch, but illegal immigrants are suspects in no more than five cases, Mr. Walczak said.

"The mayor says he doesn't need figures," Mr. Walczak said. "The truth is he doesn't want the figures because they don't support the story he wants to tell."

Afterward, Mr. Barletta said he was angered by the ACLU's defense of lawbreakers and by Mr. Walczak's attempt to minimize vicious crimes committed by people who had no right to be in Hazleton or the United States.

"A 6-year-old girl was raped by an illegal alien," Mr. Barletta said. "I wonder what he would say about these ordinances if it was his daughter."

Mr. Barletta wept before court yesterday after reading a letter in Hazleton's newspaper about the murder of a man named Derek Kichline, who was shot to death last year on a city street. Both suspects are illegal immigrants from the Dominican Republic.

"The woman who wrote the letter said the real victims -- people like Derek Kichline -- have been forgotten. I agree with that," Mr. Barletta said.

Hazleton defended its laws with some $200,000 contributed by people from across the country who side with Mr. Barletta. Their donations enabled the city to hire Mr. Kobach and four other lawyers with expertise on immigration or city codes.

Mr. Kobach said Congress had done nothing to preclude cities, counties and states from approving their own laws to fight illegal immigrants, so Hazleton's law is on safe ground. He pointed to a Virginia law that bars illegal immigrants from attending state-owned universities as proof that Hazleton should be free to try to enforce laws consistent with federal immigration policy.

Mr. Walczak countered that two judges recently ruled against city immigration ordinances after evidentiary hearings in Escondido, Calif., and Valley Park, Mo. Mr. Kobach also represented Valley Park.

Judge Munley said he would review those decisions as he pores over the Hazleton evidence.

Both the city and the ACLU say they will appeal if Judge Munley rules against them. That means, one way or another, the Hazleton case will end up before the federal circuit court in Philadelphia.