It is flabbergasting that this happened in California to a 20 year old. No wonder he lives in Japan.
I too am flabbergasted that the country with the highest per capita incarceration rate on the planet would.... oh wait.. no I'm not.
Well a good 70% of that is related to the failed (but very profitable) war on drugs. The US non-drug inmate population is comparable (albeit still higher) than many other first world countries.
You got to remember that there is lots of money in domiciling non-violent drug offenders, harden criminals not so much. The ROI% on profit-prisons is much higher (as a % of inmate population) the more non-violent offenders you can pack in.