[Ed. – It’s only one state, Arizona, but where’s the counterevidence?]
Using newly released detailed data on all prisoners who entered the Arizona state prison from January 1985 through June 2017, we are able to separate non-U.S. citizens by whether they are illegal or legal residents. This data do not rely on self-reporting by criminals. Undocumented immigrants are at least 142% more likely to be convicted of a crime than other Arizonans. They also tend to commit more serious crimes and serve 10.5% longer sentences, more likely to be classified as dangerous, and 45% more likely to be gang members than U.S. citizens. Yet, there are several reasons that these numbers are likely to underestimate the share of crime committed by undocumented immigrants. There are dramatic differences between in the criminal histories of convicts who are U.S. citizens and undocumented immigrants.
Young convicts are especially likely to be undocumented immigrants. While undocumented immigrants from 15 to 35 years of age make up about 0.81% of the Arizona population, they make up almost 8% of the prison population.