Consider the birth of sex offender registry laws, at least how we know them today. Do you think that the laws were written in the 1950s or 60s? Do you think that the people who wrote them did it as a social realization, or in response to a specific case? And do you think that if these laws were put in place due to a specific case that it would be a "normal" (if there is such a thing) sex crime?
Here are the answers to those questions. For the most part, sex offender laws are in response to a case from 1989. Obviously it's hard to say that this case is directly responsible for the laws, but as you'll see from our source article, the case from 1989 was a huge driving force. This answers the second question: yes, the laws were put together in response to a specific case.
But the last question -- it's subjective, though it would be tough to say that the 1989 case is "normal." In October of that year, a masked gunman stopped a group of three boys, one of which was an 11-year-old, along with his brother and a friend. The gunman asked them their ages. They told him. Then the gunman told the brother and friend to run away and never look back.
The boys did as they were told, though once they were far enough away they looked back. The 11-year-old was gone, as was the gunman -- and neither of them was heard from again.
It's a sad and horrific story, but in response, the boy's mother started a movement to impose stronger sex offender laws. And she was successful.
This post isn't meant to admonish the boy's mother, or to even suggest that sex offender laws shouldn't be around. Instead, it is merely meant to provide some context. Most of the sex offender laws that are in play today were made in response to a single extreme case. Most sex crimes aren't as extreme as the 1989 case, but they are punished as if they were.
Source: Slate, "Sex Offender Laws Have Gone Too Far," Matt Mellema, Chanakya Sethi and Jane Shim, Aug. 11, 2014