And you think that is right if you havent done anything wrong, do you?
Oh, you want perfection. Never going to happen. People get convicted of crimes they did not committed, its a flaw in a system created by men just like every other system created by men. In fact I'm sure men have been put to death who were innocent. To quote the great philosopher: "Life's a bitch then you die".
It's a weighing factor, generally and in the vast majority of cases the right person is convicted. You don't through out the system for the few who shouldn't have been convicted. (See the quote of the great philosopher.)
The fact that it affected you is the point.