Oh absolutely, and we'll certainly hear about it if there is evidence of foul play. For the time being, the only reason to suspect foul play is that the kid is black and it was public. People commit suicide in public all the time, depression doesn't care about your skin color, and lynchings are generally meant to send a message (so I'd expect a much more gory killing in that case).

I'm not saying they shouldn't investigate, I'm saying there's no reason yet to assume foul play. An investigation should be done regardless to find out why he killed himself (bullying? Depression?) so we can find ways to prevent it next time.