Based on f11's clarification, the Mafia's KP would move up to 3.
Which...actually isn't in the role description, looking at it now...
Note the bold. This has no connotation of adding an extra kill onto the Mafia's KP, only that the "strong kill" can't be stopped. Apple had to have gotten prior clarification to this, since this gives the same connotation as the Strongman from Paper Mario Mafia.