That post elicited a comment from LD8 State Representative John Kavanagh (R-Fountain Hills), a comment that deserves a post of its own in response.
First, his comment -
It is all but impossible to use statewide crime statistics to measure the impact of a "shadow group," such as illegal immigrants, on crime. Of course if you were so inclined, the decrease in crime between 2008 and 2009 is consistent with illegals causing more crime because that is when the jobs and illegal immigrants both began to leave Arizona. But again, it is stretching the data to arrive at any conclusion.
A better indicator, although once again not a complete one, is to compare the number of known criminal illegal aliens with their portion of the population. Using the often cited Pew estimate of 500,000 illegal immigrants in Arizona, we can conclude that they comprise about 7.7% of the population. However, they make up about 14% of persons “booked” into Maricopa County jails and constitute about 14.7% of Arizona’s prison population. Thus, known data supports the view that illegal immigrants commit more crime, beyond being here illegally, than legal residents.
State Rep. John Kavanagh
Let the spin begin.
OK, that's too snarky.
First, I want to thank Rep. Kavanagh for his comment.
I may disagree with him on pretty much everything that Ds and Rs can disagree on, but his comment was a serious one and deserves the courtesy of a serious response.
His first paragraph was actually correct, as far as it goes - the data gathered and published by the FBI doesn't specify the demographic origin of the people who committed the criminal acts that make up the statistics. The criminals behind the acts could be undocumented immigrants, legal immigrants, citizens (native born or naturalized), or little green men from Mars*.
Nor does the data explain the reduction in criminal activity, only that there *was* a reduction.
However, he should have left it at that. While Kavanagh feels, perhaps with some justification, that the crime data released by the FBI is incomplete, he tried to buttress his anti-immigrant rhetoric with statistics of questionable provenance.
He cited statistics generated by the Maricopa County Sheriff's Office (MCSO) to prove his point that undocumented immigrants commit crimes at a rate out of proportion with their numbers in society as a whole.
Specifically, he trots out the percentage of undocumented immigrants booked into county jail as proof of his position.
The problem with that? MCSO targets undocumented immigrants (and documented immigrants, and citizens who happen look like they have ancestors with some familiarity with the Spanish language) for harassment and arrest out of proportion to their numbers in Maricopa County as a whole, to the point that MCSO has sacrificed service of felony and misdemeanor warrants, a prime function of sheriff's offices all over the country, in order to divert resources and personnel to headline- and camera-grabbing anti-immigrant sweeps.
The stats coming out of the MCSO may be accurate in terms of what the MCSO does, but that doesn't mean that those stats accurately reflect Arizona or even Maricopa County as a whole.
In other words, while undocumented immigrants may make up 14% (or more) of those arrested by MCSO, they aren't necessarily responsible for 14% (or more) of the crimes committed in Maricopa County.
* - If little green men from Mars are involved, the Men In Black want to know. :)