There may be some truth to the school-to-prison-pipeline theory, and, no doubt, racial discrimination continues to be a major issue. The best way to reverse this is to press the issue of education in juvenile [and adult] correctional facilities.
Acquiring a high school or General Equivalency Diploma should be a requirement for all detained minors [and adults] who lack them, whether those requirements are fulfilled within detention facilities and/or in free society, which would hinge upon the length of time that an offender would have to serve.
When any juvenile is detained they should be required to immediately pick up where they left off in school. All time in any correctional facility should be constructively spent, from primary and secondary to post secondary education and career planning and transitioning, etc. That is or should be the reason they exist.
Compulsory education and graduation requirements should, in fact, be more stringent behind bars than they are in free society, seeing that the lack of education is so detrimental to our society, which is demonstrated in juvenile/correctional stats.