Between 1990 and 2010, the number of "unauthorized" (aka "illegal") immigrants in the US tripled.
During the same period, crime rates plunged. Specifically, the rate of Aggravated Assault (per 100,000 of the populaton) fell by helf. As did the rate of Robbery. The rate for Motor Vehicle Theft fell by 40%. (All these per the FBI Uniform Crime Reports)
Therefore, clearly, immigrants are all criminals and are the reason that our prison populations have skyrocketed. After all, since correlation is not causation, lack of correlation must be causation. Right?