This is not a "he's innocent" thread. I've defended his right to be properly judged, but that is not why I'm posting this. My understanding is that the truth on his situation is not as clean as you'd like it to be, as in he knew the guy better than suggested.
BUT...that dude is now gone. Tennessee is dealing with that for us. Certainly Shawne has other friends in that circle, but this can be addressed.
1) He's young and IMO the team not only has the ability, but also the responsibility to get involved more in his life. He might not like it but it's for his own good. He's a big investment and I'd suggest that the Pacers need to interact with him like a family member would.
Anything a good father or mother or grandparent or uncle wouldn't approve of, any action or interaction they would pursue to help him should also be on the table for the team. They need to act like they care and make sure he is shown the way to a more responsible, adult life that doesn't require him to be a jerk to his childhood friends.
Show him how to pull them out of trouble with him, rather than lingering down in their lives. Maybe a financial adviser could council him on how he and a buddy could get into a small business that gives his friend some real direction. That way he's not just living off of Shawne and starts to move into a different class of person himself, making him far more suitable as a friend of Shawne.
Don't tell me the Pacers or his agent (or some new agent) have no awareness of how to make something like this happen in a responsible way, much more than just "this is the dude that washes my car, this is the dude that mows my lawn" with all the depth of "my freeloading friends".
2) Having done that, Shawne has shown that he is the most athletic player they have. He is smooth on drives, a strong finisher at the rim (who can fly in for a dunk better than him right now), has a great shot, and has the ability to defend nearly as well as Danny (though more as a PF).
His awareness has been rough, but Granger still deals with that even now. This is what coaching, maturing and flat-out playing time help solve. Shawne has already exhibited a real savvy for drawing fouls and coming up big in the clutch. Vs Chicago we just saw him block DENG (a near AS player) and then come back to hit a big jumper at the other end in the waning minutes of the game.
3) We've got too many SFs? Well 3 is not too many when they are always playing SG/SF or SF/PF as has been the case. On top of that Shawne costs significantly less than Dun. And of the 3 Dun is by far the most one-end player. His value is high right now and makes a solid asset to adjust the roster.
Keep him (Dun) if you want since he does make the offense go, but also understand that he's not ultimately going to be the top 2 guy of an elite team. That implies building on other players, and even if Shawne isn't a top 2, he is a guy that can play INSTEAD OF Dun so that you can use Dun to help move toward getting a true top 2 prospect as part of a rebuild.
So keep Shawne, he plays a great game and gets better as time goes by, and take some responsibility with your investment rather than letting him float by. You change the oil on your car, get it tuned up, wash it, etc. That's because you CARE about keeping your investment in good shape. The Pacers should do the same with Shawne, and clearly up till now they haven't.
Get a detective, check into who else is showing up in Shawne's life, and if any other "friends" are in similar situations then you confront him with it. If he rebukes that help and insists on staying in that world fully after you've tried to help him out, THEN you send him packing with a clear conscious that you honestly tried.
Until then, keep him rather than scapegoating him for the very culture of players you brought him into.