> I’m not seeing where “U.S. violent and property crime rate have plunged since 1990s, regardless of data source” that you cited shows evidence that murder rates are reliable predictors of rates of other types of victim-having crimes?

I'm not sure if you're being purposefully obtuse here, but there's an obvious correlation between the drop in "violent crime" (homicide, murder, assault, manslaughter, etc.) and "violent victimization" (physical abuse, sexual abuse, verbal abuse, etc.). Do I have to calculate the correlation coefficient for you?

> In the scientific community, it is common knowledge that research methodologies based on statistical analyses of between-group variations is a technique that is sensitive to patterns that would not appear in a comparison with the average.

I don't believe the comparison here suffers from the law of averages. And even if it did, the difference between the two data sets' deviation isn't high enough to be of any significance.