An article in the Economist from last year, arguing for open borders says:
If lots of people migrated from war-torn Syria, gangster-plagued Guatemala or chaotic Congo, would they bring mayhem with them? It is an understandable fear (and one that anti-immigrant politicians play on), but there is little besides conjecture and anecdotal evidence to support it. Granted, some immigrants commit crimes, or even headline-grabbing acts of terrorism. But in America the foreign-born are only a fifth as likely to be incarcerated as the native-born. In some European countries, such as Sweden, migrants are more likely to get into trouble than locals, but this is mostly because they are more likely to be young and male. A study of migration flows among 145 countries between 1970 and 2000 by researchers at the University of Warwick found that migration was more likely to reduce terrorism than increase it, largely because migration fosters economic growth.
Is the highlighted claim about the US (America = USA, no doubt) found[ed] in credible research? It obviously doesn't mesh too well with US presidential claims... and the difference in odds claimed is pretty large (and not fitting the pattern from some EU countries, mentioned in the next sentence.)