A suggestion that Kevin (or somebody) should look specifically at domestic violence. That's probably a tough one as changing cultural norms (sadly) are going to impact actual data on that, but my take is that it isn't so much that lead turned people into "criminals," it's that it turned them into violence-prone assholes. Obviously violence is generally a criminal act and domestic violence is hopefully treated as a criminal act, but I guess the point I'm trying to make is that relative to the frequency other violent crimes it's probably a pretty direct measure of "violence-prone assholeness."
