At this point in the investigation, there is zero evidence that he abused children, although it's true he seems to have spent much of his adult life hanging around youngsters.
When he was 19, Karr legally married a 13-year-old. When he was 23 or 24, Karr remarried, this time to Lara Knutson, who was 16.
A few years ago, he was arrested on a MISDEMEANOR charge of possessing child porn.
Beyond these facts, we know virtually nothing about the man other that what he has said about himself, and we can't take his word as gospel.