As an individual, yes, horrible and unforgivable is the response.
However, I don't think giving up our rights because some "junkie" decided to murder a child is a good or necessary thing to do.
What you're asking is to give up our rights for a single possible case of a person doing something horrible. No, we have a system that punishes that person already. We don't need to restrict peoples rights to prevent a rather uncommon thing from happening in the future.
You can not stop a mentally ill person or a criminal from doing something horrible. If they are going to do it, then they will find a way to do it.
The trick is to recognize the symptoms. Sometimes it is almost impossible to recognize it, but it is possible. Education can help in this case, too.
But to track people who are innocent and basically call them potential criminals before any crime is committed, is asinine.
