Credit: Sandy Hook VOA / Wikimedia CommonsCredit: Sandy Hook VOA / Wikimedia CommonsHow do you solve a problem like mass shootings? The answer, writes Gene Healy, is one that, understandably, few people want to hear: You probably can't. That's the logical, if grim, conclusion to be drawn from a new Congressional Research Service Report on "Public Mass Shootings in the United States." The tragic fact is, there's not a great deal that public policy can do to avert spree shootings.