Мафия 15. Cosa Nostra.

…When we entered Ottavio's house, the local fruit merchant, we found the owner lying on the floor in a pool of blood. The bullet wounds on his abdomen formed a six-pointed star – the killer took his time and put in the effort, perhaps to instill even more fear in our hearts…

It seems like it could be the Mafia, Jews, or Satanists. There's clearly a clue, but I can't find anything yet.
I missed the mark with Brackman; I knew something was off here.
I haven't found anything about the serial killer's murder yet, and something tells me that Ali's quote isn't related to boxing in this case.