FBI crime figures reported in today’s Wall Street Journal challenge the perception that illegal immigrants have unleashed a crime wave in Arizona.

One of the clinching arguments for Arizona’s tough new law aimed at illegal immigration has been the perception in that state that crime has been rising, and that undocumented workers are largely to blame. Yet the Journal reports that the incidence of violent crime in Phoenix last year plunged 16.6 percent compared to 2008, a rate of decline that was three times the national average.

According to the Phoenix Police Department, the downward trend in crime has continued into 2010 even as the “illegal immigrant crime wave” story reverberates on cable TV and talk radio. As the Journal story reports:

In Phoenix, police spokesman Trent Crump said, “Despite all the hype, in every single reportable crime category, we’re significantly down.” Mr. Crump said Phoenix’s most recent data for 2010 indicated still lower crime. For the first quarter of 2010, violent crime was down 17% overall in the city, while homicides were down 38% and robberies 27%, compared with the same period in 2009.

Arizona’s major cities all registered declines. A perceived rise in crime is one reason often cited by proponents of a new law intended to crack down on illegal immigration. The number of kidnappings reported in Phoenix, which hit 368 in 2008, was also down, though police officials didn’t have exact figures.

The new crime figures confirm what I wrote in a column in today’s Washington Times under the headline, “Unfounded fear of immigrant crime grips Arizona,” and what I explored in a longer think piece, “Higher Immigration, Lower Crime,” in Commentary magazine a few months ago.

The president and Congress need to fix our immigration system, but we need to do it in the right way and for the right reasons.