the first rapper to rap about it....or the first one that you actually listen to that mentions the case in a released song? There's a difference.
Personally, I'd like to see something like...."Self Destruction" Just one hard beat, or even a pre-released beat, with 5-10 dudes on it....8 bars.
Nas, Wale, Lupe, J. Cole, Jay-Z, Joe Budden, etc... Jay might not do it, but the other folks, I think they'd be for it.
Damn if I had a billion, I'd fund the project. Maybe something like a story telling track on the events that happened that night....then a conclusion verse.