You have stated that before and it is true, but I find that a lot of the times it was the mothers boyfriend or uncle or family friend but in a dysfunctional family where the need for going out outweighs the caution. In other words the wolf was invited in just because there was some free babysitting available. Understanding this might help some what. Your post only mentions access as one of the conditions but does not expound on it. I find a lot of times that access was too easy and think it bears some study. And if it helps it would be a good thing. Some times people let down their guard because even though there is a history they think they would not do it to family or believe they were falsely accused. From the article it is possible to "assume" he was in the house a lot. I did say assume, the article needs to fill out the story some.