There are two reasons our leaders roam scot-free despite all their crimes. I call it the King and Robin Hood system. First, our leaders are like little kings. They are elected but they are not accountable. Just like erstwhile kings, once in power, they are free to use the kingdom to their advantage. The laws are meant for the common people, not for them. Yes, our kings keep changing through the election process. However, whosoever gets the seat is free to raid the republic. We are not a democracy; the more apt name would be kingocracy. And our politicians being tried, punished and made to bring their money back from Switzerland would not be very king-like at all.
From Chetan Bhagat's article Of Ravages and Kings in Times of India. More Here