Sure doesn't seem like enough time for someone who was initially charged with capital murder. I guess they took his age at the time of the incident (17) into account. Not sure how tough the prisons in MS are, but it'll be a few years before he gets out. Regardless, this kid will not have freedom during what could have been the best years of his life.
What's really sad is that if he survives prison he will probably come out being stuck in some gang and go out and hurt someone else. Hopefully it works the other way but I'm betting that 25 years he will serve will only make him more a danger to society