As Arizona Gov. Jan Brewer last spring signed her state’s landmark bill cracking down on illegal immigration, she listed crime as her biggest reason.

Her signature, she said, aimed to solve a “crisis (of) border-related violence and crime due to illegal immigration.”

If she’d gone to the one Arizona city that confronts Mexico most directly – Nogales, where the border separates the town into American and Mexican components – she’d have discovered the connection she claimed simply does not exist.

In 2000, Nogales, AZ, experienced 23 rapes, robberies and murders. Last year, after 10 years of population growth mostly through illegal immigration, there were 19 such crimes. Aggravated assaults dropped by one-third. There have been no murders for more than two years.

So much for the immigration-created crime wave.

Violence? Well, Occasionally

Yes, there is crime aplenty in Mexico, especially drug-related crime in cities like Tijuana and Juarez on the south side of the border. But illegal immigrants have not brought that with them. Many, in fact, come to America to escape it.

Yes, there is the occasional violent crime along the border. A Cochise County rancher was killed in March, possibly by a drug smuggler, although no one knows that for sure. A sheriff’s deputy in Pinal County was shot and wounded in April, allegedly by illegal immigrant drug runners. But every law-enforcement agency along the Arizona sector of the border says drug cartels normally don’t target U.S. residents.

Anti Feeling Is Contagious

“This is a media-created event,” Sheriff Clarence Dupnik of Pima County (Tucson) told the Arizona Republic newspaper. “I hear politicians on TV saying the border has gotten worse. Well, the fact of the matter is that the border has never been more secure.”

That is one reason federal apprehensions of illegal immigrants are lower this year than they’ve been since the 1990s.

It’s not merely politicians in Arizona who have tried to exploit a non-existent link between violent crime and illegal immigration (no one denies that crossing the border surreptitiously is a crime, but it’s not a violent one).

That alleged link became a major theme of the California Republican primary election battle between Steve Poizner and Meg Whitman last spring. But there is no link, according to the latest research on the subject.

That research comes from University of Colorado sociology Prof. Tim Wadsworth, whose research on crime and immigration completely debunks the notion that more immigration necessarily equals more crime. Wadsworth, of course, would be the last to deny that some immigrants, illegal or not, are criminals and even violent criminals.

But here’s what he reported in the April issue of the academic journal Social Science Weekly :

“Cities that experienced greater growth in immigrant or new-immigrant populations between 1990 and 2000 (Los Angeles, San Francisco, Fresno and San Diego were among those with the greatest rise in migrant populations) tended to demonstrate sharper decreases in homicide and robbery. The suggestion that high levels of immigration may have been partially responsible for the drop in crime during the 1990s seems plausible.”

Wadsworth worked only with statistics from the 1990s, a decade for which the numbers are complete. But the same cities that saw the most foreign immigration in that decade also were the leaders in the next 10 years, and in most of them, violent crime continued its downtrend.

Wadsworth didn’t stop with just the big cities, though. He looked at 459 communities with populations of at least 50,000. He said distinguishing the effects of legal and illegal immigration is difficult, as the last two U.S. Census reports did not track those numbers. But he noted that immigrant citizens and non-citizens often congregate in the same areas for reasons of culture and language. He tracked robberies and homicides because they are harder to hide than other crimes.

Rather than causing crime waves, Wadsworth says, the numbers suggest that “immigration may be partially responsible for the decrease in violent crime.” His statistical analysis shows that growth in the new immigrant population led, on average among the 459 cities, to a 9.3 percent decline in the murder rate and a 22.2 percent decrease in robberies.

Wadsworth, however, does not expect his pioneering research to change political rhetoric. “The association between immigration and crime has been a center point of anti-immigrant discourse since the 1880s,” he said. “Although there has been scant empirical research to support such claims, they have persisted with little debate.”

Now there is some research. But politicians who exploit the supposed – and, it turns out nonexistent — link between increased crime and illegal immigration mostly likely won’t change their tune. It’s been too useful.

Which means it will now be up to voters to see through the false rhetoric and act accordingly.

Mr. Elias may be contacted at tdelias@aol.com.

His book, “The Burzynski Breakthrough,” is available in a soft cover, fourth edition. For more Elias columns, visit www.californiafocus.net