"An often rocky relationship with his mother, caused in part by her drug abuse, forced him from his home on several occasions during his high school years in High Point, N.C. Sometimes, he bounced from one friend’s house to the next for three or four months at a time. The instability helps explain why Dewitt only played one year of high school basketball at T.W. Andrews High School and why he never graduated."
http://www.columbiatribune.com/news/2009/jun/30/dewitt-waiting-hardest-part/
He didn't qualify at MU simply because the prep school he was attending was discredited by the NCAA and thus the classes he passed their didn't count towards eligibility. It was the same prep school that both Zaire Taylor and Justin Safford came from, they were just already in college at the point the NCAA discredited the prep school's credentials.