So? No one has said that poor people turn to thefts or other crimes. Different factors will play a role, and no one here has discounted that the person himself has responsibility. There's also discrimination on the other side. The poor will be overrepresented in the criminal justice system because of inherent discrimination. It's more difficult for them to afford legal counsel, yet at the same time, many do not qualify for legal aid. Hence, they have to represent themselves to the best of their ability, which isn't going to be very well. It's also more likely that you will be given more lenient treatment if you're of a particular race and social status.
It works both ways. If it's ultimately people's choices though, what's causing the poor and minorities to commit all these crimes, since based on a percentage of population, they are overrepresented in the justice systems. If it was just people making the decisions, then it should be more uniformly distributed, as it'd be more random. But it's not, not by a long shot.
I am not even sure how this is an example of anything.