https://cis.org/Huennekens/DOJ-26-Federal-Prisoners-Are-Aliens The majority of federal inmates that are illegals (not just immigrants, I understand the difference) are there for additional offenses besides immigration offenses. They tack the immigration stuff on after arrest, of course. Meanwhile 49 out of 50 states don't report on immigration status so we could only guess about their rate of criminality on the state and local levels. I'd guess it's about the same.  Cato is promoting a left wing agenda, and is obviously just as misleading as the right wing agenda from OP.