There is no national database that compares crimes committed by immigration status. In fact, only one state – Texas – does so. That means there’s no national database that breaks down crimes committed by native-born citizens or immigrants, or those in the country illegally, making it difficult to confirm or dispute [Trump’s] numbers.
What available studies do show, however, is that overall, crime rates are lower among immigrant groups than they are among native-born Americans.
…Comparing overall crime rates for different groups is the best way to determine if a particular group poses a significantly greater threat than others.
…Trump doesn’t include a comparison to the general population [of Texas’s] crime rates, and the numbers Trump cited are arrests, meaning all did not result in convictions.
…Undocumented immigrants were convicted of 5.9 percent of all the homicides in Texas, legal immigrants were convicted of 3.8 percent of homicides, and native-born Americans were convicted of about 90 percent of all the homicides in Texas.
…The information Trump appears to be using does not make clear what year the arrests were made, when the crimes were actually committed, and combines charges with convictions.
According to the data, serious drug and DUI offenses represent the largest group of convictions, followed by immigration and traffic offenses.