Then that guy can kill him or make him do what he wants to do, but you don't have the right to make someone else do it.
Also, people would refuse service with the rapist.  The family of the person who was raped and murdered could expose the rapist.  People would be on the lookout for the rapist and make sure the rapist was isolated from everyone else.  The rapist would eventually starve in a voluntary society.  Meanwhile, people could voluntarily provide for their own security.
The Child molestor or the rapist could be killed by the victim.  Hire a security guard when you're around the rapist.  Have the rapist do things when you're not around.  Hire someone to direct the rapist to do what you want them to without actually meeting the rapist.
		
		
	 
LOL. 
It seems great until you get bogged down in the details, doesn't it? 
Who would decide what a crime was, and how much was owed? What is the standard of proof compared with current 'civil' and 'criminal' courts? 
What is a rape worth? Does it matter if the victim was a virgin? What if they were a wife, who was a virgin when she was married? 
What if the victim is a man? Who happens to be gay, and not a 'virgin'? 
Now go through this process for every possible crime. And remember, you're offering slavery, and in some cases the right to kill - not a relatively simple 'catch-and release' program. 
At least we'll have enough work for all those laid-off prison guards, administering this. Probably enough for the IRS jobs you want to eliminate as well
