How about the fact that he started sleeping with his first wife when she was 12?
That's really not at issue, however consider Karr's age at that time and the fact that both the girl involved and her parents had to have consented to the marriage. Once married there was no illicit act on the part or Karr, his young wife or her parents.
My grandparents were married when my grandfather was 24 and my grandmother was 14. No crime was committed and my grandfather was far from a child molester- he was a minister in the Moravian church. They remained married until the death of my grandmother at the age of 76.
I spent some time in Morristown, New Providence and East Orange New Jersey. I know of many young ladies in New Jersey who are married in their early to mid teens. I don't really agree with that situation, but it doesn't make it illegal or even immoral, just ill-advised.......