Kevin Drum may be undergoing some intense medical treatment, but a Washington Post article made his day. Freddie Gray’s life a study in the sad effects of lead paint on poor blacks
Drum's 2013 story at Mother Jones and follow-up reporting detailed research making a pretty good case that exposure to lead in gasoline and elsewhere (Paint as in Gray's case) has serious effects leading to violent criminal behavior among other things. The use of lead in gasoline and its removal tracks almost precisely changes in violent crime rates - with a roughly 20 year lag as the effects of exposure in children affect them as they become adults. The latest research shows there appear to be no safe levels at which the effects of exposure to lead can be ignored.
We no longer put lead in gasoline, but we still have the crime policies in place that reflect that toxic era. As Drum concludes
This is important, because even if you're a hard-ass law-and-order type, you should understand that we no longer need urban police departments to act like occupying armies. The 90s are gone, and today's teenagers are just ordinary teenagers. They still act stupid and some of them are still violent, but they can be dealt with using ordinary urban policing tactics. We don't need to constantly harass and bully them; we don't need to haul them in for every petty infraction; we don't need to beat them senseless; and we don't need to incarcerate them by the millions.
We just don't. We live in a different, safer era, and it's time for all of us—voters, politicians, cops, parents—to get this through our collective heads. Generation Lead is over, thank God. Let's stop pretending it's always and forever 1993. Reform is way overdue.
To the extent that cities like Baltimore still have a legacy of lead in old buildings and in the environment from air pollution, lead is still going to be a factor. Blaming what happens on social failures, government policies, etc. may not be entirely off the mark - but the legacy of a deliberate poisoning of people for profit (as Neil deGrasse Tyson showed in "The Clean Room" episode of Cosmos) is one we still need to keep in mind.