Not all of those first crimes are violent. The US incarcerates more of its citizens than any other country in the world. We are the world's jailer. Prison rates in the US are the world's highest, at 724 people per 100,000. 

The  "for profit"  Prison Industrial Complex is one of the fastest growing industries in the USA. It's profitable to keep people in prison. Many are imprisoned for low level drug related crimes as a result of the nation's war on drugs.

Our drug laws are set up to discriminate: "Federal law stipulates five years’ imprisonment without possibility of parole for possession of 5 grams of crack or 3.5 ounces of heroin, and 10 years for possession of less than 2 ounces of rock-cocaine or crack. A sentence of 5 years for cocaine powder requires possession of 500 grams – 100 times more than the quantity of rock cocaine for the same sentence. Most of those who use cocaine powder are white, middle-class or rich people, while mostly Blacks and Latinos use rock cocaine.