if(event.getEntity().getLastDamageCause() instanceof EntityDamageByEntityEvent)
        {
            EntityDamageByEntityEvent EDeath = (EntityDamageByEntityEvent)event.getEntity().getLastDamageCause();
            if((EDeath.getDamager() instanceof Player))
            {
            Player player = (Player)EDeath.getDamager();
		//Do stuff
	}
}