How much did race and class affect the Georgia case where a 16 yo girl received a 40 year sentence for accidentally shooting a man during a robbery gone bad?

Please note that this is not a loaded question, where I’m trying to elicit certain answers to reinforce a personal bias.
I read this story as a news item, and I was shocked at the severity of the sentence, so I searched for images of the people involved, then saw a bit about the history of the victim and noted the location of the incident, Georgia.
I was left wondering if I missed some information that would account for the severity of the sentence given the age and intent of the shooter.

Georgia teen sentenced to 40 years after killing man for a Playstation 4 in Craigslist robbery