In my father, I have observed the day-to-day antics of a child molester at close range. As a child, I observed this behaviour without knowing of his predilections, and I didn't learn of the sinister aspect of his personality until I was almost a teen. Here are some red flags to look out for when there's a family acquaintance/friend/relative in proximity to your kids:
1. Overly interested in your children (duh!).
2. Appears more comfortable with children than with adults.
3. Appears to prefer the company of the kids than the adults.
4. Prefers to do "kid-oriented" activities with the kids (eg. swimming, playing video games, summer sports) rather than do adult things with other adults.
5. Offers to take your kids on fun "outings".
6. Interested in music/movies/t.v. that would normally only interest children, and engages children in conversations about their own interests.
7. Offers to babysit your kids.
Most of these are probably painfully obvious, but I can tell you that my father slipped by the radar of numerous family members using these techniques. Granted, in 99% of the above situations, there was no molestation taking place and there were other adults present. The majority of children that my father spent time with had no idea what he would eventually be convicted of, and as adults, would be shocked to learn of what he did. But a molester could use the above techniques to "groom" his victims, assessing their vulnerabilities, and gaining the trust of their families. Eventually, in the right circumstances, the trusted family friend could become the perverted uncle who molests your children.
On the blog "Finally Stopped Running", on the same topic earlier today, blogger Pronoia Agape posted a comment with following observation:
"I read the results of a study based on the responses from sexual predators themselves to the question on how they choose their victims. They all answered the same and they all had astoundingly developed predatory instincts. Children who are unlikely to tell their parents, or unlikely to be believed, were selected prey. Children who didn't even know the names for sexual organs and thus seemed unlikely to ever dare discuss something like this with their parents.
Unless a child is randomly ambushed in the school yard - which is the least likely scenario, as most predators KNOW the child before they attack - the "non-offending" parent bears at least a portion of responsibility, even only by being unconcerned and distant enough for this to be made possible. For the child to feel like she can't immediately tell, be believed, and the predator arrested - and the predator sniffs out kids who feel like this."