I can see it happening, though Seth probably isn’t the culprit. And, also, has anyone considered Montgomery? In his Season 3 picture, his newspaper says that he was antagonizing Bryce. This doesn’t sound like much, however, we all know what antagonizing led to when it came to people like Tyler. In addition to that, though Monty at one time thought of Bryce as the one good person in his life, in the Season 2 final episode, Bryce betrayed him. This maybe left Monty very angry, possibly even more angry than at Tyler, since Bryce was the one good friend he had. He is angry and violent by nature, so, maybe, he was the person who killed Bryce. This would be an excellent plot twist, and a plot twist that makes sense, since Monty had lost all his friends, and the loss of Bryce may have been the last straw. Also, consider Hannah’s mother. In season 3, Hannah’s mom mentions that she wants Bryce dead, and we see her using a gun at a shooting range prior to that.

Very true Dipshit, no insult intended. But maybe it could also be Marcus. Remember he called out Bryce as a rapist and probably ruined his future. So he maybe could have wanted revenge