MELISSA BLOCK, HOST:
This is ALL THINGS CONSIDERED from NPR News. I'm Melissa Block.
AUDIE CORNISH, HOST:
And I'm Audie Cornish.
We begin this hour with one fundamental disagreement that complicates the debate over immigration. Do undocumented immigrants increase crime rates? Politicians from Pennsylvania to Arizona say they do.
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GOVERNOR JAN BREWER: They're devastating our ranchers down in Southern Arizona: drop houses, kidnapping, automobile accidents, extortion, drugs.
CORNISH: That's Arizona Governor Jan Brewer speaking a few years ago on Fox News. Some social scientists tell a different story. They argue that the numbers show first-generation immigrants make communities safer, as NPR's Joel Rose reports.
JOEL ROSE, BYLINE: A street singer accompanies himself on accordion outside a new Mexican restaurant in the Sunset Park section of Brooklyn.
UNIDENTIFIED MAN: (Singing) (Foreign language spoken)
ROSE: Twenty years ago, this neighborhood was nicknamed Gunset Park because of high crime. Empty storefronts were everywhere. Now, the commercial avenues are bustling, full of stores catering to immigrants from Latin America and Asia and their young families.
DR. PHILIP KASINITZ: When a lot of immigrants come to communities, crime tends to drop, and, of course, it's quite the opposite of what many people think.
ROSE: Philip Kasinitz teaches sociology at the City University of New York's Graduate Center. Police statistics show that Sunset Park is much safer than it was 20 years ago. Homicides are down more than 90 percent. Crime rates have dropped all over New York since 1990, but especially in neighborhoods that have high immigration. To be fair, Kasinitz says there may be lots of reasons for that, including changes in policing and the end of the crack epidemic.
KASINITZ: It's absolutely not something you can attribute to any one cause. But I would say among the things that are on the positive side of the ledger has been this dramatic increase in immigration. The fact that you've got more people, that you don't have empty storefronts, that it's not deserted, sort of decreases the conditions that can create crime.
ROSE: And it's not just New York. Across the country, cities with high rates of immigration - Los Angeles and Houston and San Diego - also have much lower crime rates than they did 20 years ago. Some social scientists believe this is not a coincidence. Robert Sampson at Harvard University argues that first-generation immigrants make their communities safer by working hard and raising families.
ROBERT SAMPSON: You don't migrate to the United States from countries around the world on a whim. It takes planning, and, for the most part, it is driven by economic motivations. People want a better life. They're seeking to get ahead. And those are the very factors that tend to be associated with lower crime.
ROSE: Sampson says this seems to be true whether the immigrants have entered the country legally or not. But some say there is a difference when it comes to crime.
REPRESENTATIVE LOUIS BARLETTA: You cannot intermingle immigrants with those that are in the country illegally.
ROSE: Lou Barletta is a congressman from Pennsylvania and the former mayor of Hazleton, a small city in the northeastern part of the state. In 2006, one of Barletta's constituents was murdered allegedly by a man who was in the country illegally.
BARLETTA: The shooter was arrested eight times before he came to Hazleton. Should not have even been in the country, let alone in our city, taking the life of an innocent man. That was the final straw.
ROSE: Hazleton passed laws that made it a crime to rent to or hire undocumented immigrants. Those laws are still tied up in court. Pennsylvania is not the only state where lawmakers have tried to curb illegal immigration in the name of public safety. Here's Arizona Governor Jan Brewer defending her state's crackdown on undocumented immigrants on Fox News in 2010.
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BREWER: We - I've been facing this crisis, and it's devastating on the people of Arizona. And I feel as governor I have a responsibility to protect the citizens. We've been inundated with criminal activity, and it's just - it's been outrageous.
ROSE: But Brewer's critics say there's simply no evidence that illegal immigrants are driving up crime rates. And even the Center for Immigration Studies in Washington, which opposes increased immigration, came to the same conclusion. Jessica Vaughan is the center's director for policy studies.
JESSICA VAUGHAN: There's no evidence that immigrants - or even illegal immigrants - are necessarily any more or less likely to be committing crimes than the population at large. It's just that they tend to be associated with certain types of crimes, drug trafficking, for example.
ROSE: There is evidence that immigrants are overrepresented in local prison systems in Arizona and elsewhere. But overall, violent crime is actually lower than you would expect along the U.S. border with Mexico. That's according to Ramiro Martinez, who teaches criminology at Northeastern University.
RAMIRO MARTINEZ: In Texas, homicides are actually a little bit lower in border counties than they are in the rest of the state. Not only in Texas, but also in New Mexico and Arizona, in California - more immigrants means less crime.
ROSE: That finding may run counter to the public perception that immigrants contribute to higher crime rates. But if lawmakers in Washington look to the research of Martinez and others, they'll find a growing body of evidence to the contrary. Joel Rose, NPR News, New York. Transcript provided by NPR, Copyright NPR.