1. How do it?

    Code:
                                if(headshot)
                                {
                                    var kills = Core.Database.Sql.Builder.Append(@"update pvp set hs=hs+1 where steamid=" + killer_identity.SteamId.ToString() + ";");
                                    _mySql.Update(kills, _mySqlConnection);
                                }
     
  2. Hey mate, did you still want to figure this out or have you done it already?
    In either case it's actually quite easy. In the arg "EntityEffectSourceData" from the OnPlayerDeath hook contains all the info you need. In this case EntityEffectSourceData.Hitbox will return the enum of EHitboxItem and give you where they were shot. You could then just do a case for multiple, or an if statement, whatever you choose based on the returned value.

    Good luck :)