Below certain numbers, it might be relatively harder to reduce some crimes than others. For instance, there might always be people who are determined to kill th

Below certain numbers, it might be relatively harder to reduce some crimes than others. For instance, there might always be people who are determined to kill their spouse; but it might be easier to reduce the number of people who see stealing things as useful. I don't really know, but it would be interesting to see some numbers. Is there some kind of minimum murder rate that can't be lowered further just with laws (i.e. some more fundamental cultural change is required)? If so, then we might be approaching that minimum (for the current US culture/society) and that could explain why they aren't decreasing much any more.