According to a recent report by "The Economist", "... first-generation migrants commit crimes at lower rates than natives."
Any statement about sociological phenomenon must be qualified by ethnicity and race, for differences in culture and genetics produce stark differences in behavior among ethnic and racial groups. If the author of a demographic statement omits such qualifying information, then he is deliberately trying to hide ugly facts about a particular ethnicity or race.
Contrast the demographic statement by "The Economist" with the statements by David Frum, the senior editor at "The Atlantic". In an essay, he wrote, "Refugees from the communist crackdown in Hungary in 1956 have flourished in America. More than a quarter century after they began to arrive in America, Somali refugees have not. First-generation Japanese immigrants committed crimes at rates much lower than that of other Americans; Mexican immigrants have historically offended at elevated rates."
His comments about a sociological phenomenon are clear and cogent because he qualifies them by ethnicity and race. Specifically, both Africans and Hispanics are less likely to assimilate than Europeans and Asians. Uncontrolled immigration from Central and South America threatens the United States.
This observation is buttressed by a sociological study that estimates the rate of arrest for murder and that uses data provided by the Federal Bureau of Investigation (FBI) and the Pew Research Center for 2013. This study examines the rate (of arrest) by ethnicity and race. This rate is approximately proportional to the number of people murdered (per year) by each ethnicity and race and can be viewed as a proxy for the latter rate.
The arrest rate for Asians is about half of the rate for non-Hispanic Europeans.
By contrast, the arrest rate for Hispanics is about 3 times the rate for non-Hispanic Europeans. The arrest rate for Africans is about 9 times the rate for non-Hispanic Europeans.
The above facts lead to an inevitable conclusion: Donald Trump is right -- again. We must promptly deport illegal aliens (of whom most are Hispanic) and restrict legal immigration. We must favor immigrants who "support this country and love its people and its values."