[quote=@mskennedy615]
[@BrutalBx] 

I can definitely see that happening! Keisha's ex showing up to the school with a gun, only really looking for her brother but shooting anyone that gets in the way. Sounds....exciting. 
[/quote]

More than likely, the brother was the target, then the guy realises that he's now trapped with police on the way so he gets scared, starts taking out anyone that gets in his way, probably hopped up on some drug.