Yes, everyone is responsible for their own actions. If society wants its citizens to fit into a certain framework, than society should be responsible for teaching that framework. If it fails to teach it the first time, it is still responsible until it gets it right. The very fact that he is in prison is evidence he is not fully aware of how and why to fit into that social framework. Without doubt, this is over simplifying a large, complicated problem and does not explain all cases.
Black males are the major portion of the prison population.
Although there has been large strides for equal rights in the past few decades, blacks still get less education, have lower paying jobs and are denied the other normal opportunities of whites. Then it is not the fault of the black person in jail as much as it is the social system into which he was born. The prison system could be much better at rehabilitation but it is caught in its own faulty system. Much of the blame of the system's shortfall can be blamed on the government bureaucracies to which it is accountable. It needs change and dramatic change.