Where did the phrase "get off scot free" come from?

Since the answer has already been given and I no longer have to fear violations for "chatting," I just wanted to say that seemingly little things like this is what I'll really miss about this site...

In the olden days, people wanted for theft, sexual offences such as incest, bestiality or rape,  those who were wanted for animal cruelty or child abuse etc. would travel North of the Scottish border, where the laws were not enforced and social deviants could find sanctuary.

One of my schools. The 10th, or the 11th, I can't remember. Anyway, me and a couple of mates were beating on this guy because his dad was a conservative voter and a teacher came up and said "Hey - get off Scot Free". Actually, his name was Bob Smith, but the story sounds better if........ oh, you know.

Use Google to search for the word "etymology" and the phrase "scot free". It ain't exactly rocket science. I just did that and found the answer in under 10 seconds. Self-reliance is a good skill to have and will imprve your life. 

It comes from the Scandinavian word skat that means tax. It goes back to the 10th century. 

Scot refers to a tax that was imposed 100's of years ago .  The wealthy were to pay the tax and the poor were to benefit from it.  Of course not all the wealthy paid the tax and so they 'got away scot free' (tax free).

Sounds like a modern problem to me.