This sounds to me like a blatant attempt to discredit the Human Rights Act (even further).
As for Sarah's Law ..... Let me tell you a story. Once upon a time I visited a large electrical retailer in my home city to buy a washing machine. I chose the model I wanted and went to the desk to discuss my payment options. All seemed to be going well, until ..... "COMPUTER SAYS 'NO'!" I was refused credit, on the basis that a former occupant of my address had run up substantial debts.
Being turned down for credit in front of a store full of customers -- all of whose eyes I could feel turning on me, staring at me, drilling into me -- for the actions of somebody else far beyond my control felt bad enough. A false positive under "Sarah's Law" (which, by the way, would not even have helped Sarah Payne) is a horror I can't even begin to imagine.
Anyway, either someone has learned their lesson and repaid their debt to society, in which case they deserve exactly the same rights as if they had never been convicted; or they haven't, in which case they deserve still to be in prison.