30% of our prisoners are illegal immigrants, so our incarceration rate is inflated by people who should be in jail in Mexico and Central America
We cut the number of mental health beds to a fraction of the total of the 1950s though the population has grown. Many of those in jail should be in psychiatric institutions instead of jail, but there is no where else to house them.
When the mentally ill and illegal aliens inflate your numbers, the numbers look far worse than they really are.
Close to 30% are non-citizens. That does not mean they are all illegal immigrants. A number of them are in legally but are in prison for other offenses like murder, robbery, etc.