Long time no post, but since I grew up with Aaron (well, DJ really since we're the same age):
In Bristol it's easy to come from a good family and get caught up with the wrong people. You grow up playing sports with them, you become friends with them, and you don't really realize until around middle school that they're not the best stock, but by then for some kids it's too late, they're your friends. And in Bristol there's this mentality, like many other towns, that you impress you friends with drugs and alcohol. It's easy for kids to get dragged down by this stuff.
Also, and this may be hard to believe, but he was ALWAYS in his brother's shadow until about his sophomore/junior year when his football career started to really take off. DJ was near legendary growing up. We had five plays in youth football, DJ go left, DJ go right, DJ go short, DJ go long, DJ up the middle. In the sport of basketball he was near untouchable at his age, and well, he got the adulation for that.
Aaron was an uncoordinated kid growing up and would try to keep up with his brother but never could, and with his father's passing it's just really easy to see how he could be mixed in with the wrong crowd. A father dying and your older brother gets all of the praise, it has to be tough. It's terrible but it happens. I'm thankful that DJ still has his head on straight.