The Trump administration regularly asserts that undocumented immigrants are predatory and threaten public safety. Immigrant advocates say that talk demonizes an entire class of people.This is what is called a "null result". It doesn't explain anything, except that some naive search for a correlation failed.
Now, four academic studies show that illegal immigration does not increase the prevalence of violent crime or drug and alcohol problems. In the slew of research, motivated by Trump's rhetoric, social scientists set out to answer this question: Are undocumented immigrants more likely to break the law?
Michael Light, a criminologist at the University of Wisconsin, Madison, looked at whether the soaring increase in illegal immigration over the last three decades caused a commensurate jump in violent crimes: murder, rape, robbery and aggravated assault.
"Increased undocumented immigration since 1990 has not increased violent crime over that same time period," Light said in a phone interview.
The research is paywalled, so I can't say for sure.
NPR reported this 5 years ago:
Twenty years ago, when brain imaging made it possible for researchers to study the minds of violent criminals and compare them to the brain imaging of "normal" people, a whole new field of research — neurocriminology — opened up.Here is some research on the causes of violent crime.
Adrian Raine was the first person to conduct a brain imaging study on murderers and has since continued to study the brains of violent criminals and psychopaths. His research has convinced him that while there is a social and environmental element to violent behavior, there's another side of the coin, and that side is biology.
"Just as there's a biological basis for schizophrenia and anxiety disorders and depression, I'm saying here there's a biological basis also to recidivistic violent offending," Raine, a professor at the University of Pennsylvania and author of the new book The Anatomy of Violence: The Biological Roots of Crime, tells Fresh Air's Terry Gross.
If this is correct, then we should pay attention to who has the genes for violent crime. The question is not whether the immigrants have the proper papers, but whether they have the bad genes.
Looking at averages is not the best measure. Maybe averaging Pakistani and Chinese immigrant crime rates gives about the same as averaging black and white crime rates. That would not justify our stupid immigration policy.
My guess is that illegal aliens do have lower crime rates than their kids. That appears to be the case where I live.