People pursuing progress and education don't often end up in the prison system, and people pursuing the prison system usually aren't pursuing education with the same fervor that they are pursuing crime.
I've long believed that people who are in financially disadvantaged areas are using too many excuses for why they can't get ahead. The schools are usually easier to succeed in when the schools aren't as good, which should make it easier to pass with honors. The onus is on the student to study for college entrance exams and the like. But between the Pell Grant and with all of the scholarship programs out there, there isn't much of an excuse, it's really just laziness. Maybe you have to work harder than the rich kids who's parents send them to school outta pocket, but there's no reason you can't go out there and get yours.
The Private Prison Industry charts children from elementary school. As recent as a few years ago, for decades, the prison corporations were using 3rd grade students test scores to determine how large to grow their prison facilities. Now, they have moved beyond that and are observing them from the onset, kindergarten. This would raise the question, who is actually behind the creation and implementation of "standardized" testing?
Aside from that aspect, it is easy (and incorrect) for those of us who never have been in a disadvantaged school system (one that does not provide books, computers, or a success driven structure) to make such claims that "children are lazy" or "...there is no excuse," but that is negating various factors not only within school systems, but also within various socioeconomic conditions.
Another part of the School to Prison reality is that many private prison corporations have contracts with the governments the prison is associated with that guarantees the prison population capacity at their complexes. This means that your local government officials, law enforcement officers, prosecutors, and judges are all controlled by the laws set forth by the corporate lobbyists (via corporate lawyers) influence upon the creation and control of law. Major non-prison corporations profit from prison labor, including entities such as Boeing, McDonald's, Starbucks, etc. with prisoners making less than $4/day for their labor.
Slavery is still alive and well.