Мафия 15. Cosa Nostra.

That's exactly what I mean, because if the Mafia were blocking Arando, what was the point of killing him?

And that's actually possible. If the Mafia suspected Arando of being the killer, they might have blocked and killed him to avoid casualties within their own ranks. And if that's the case, Ar clearly offended someone in the Mafia with his posts.