Yesterday's horrific string of homicides in Alabama inevitably will be cited as an argument for more gun control, especially a new federal ban on "assault weapons." Geneva Police Chief Frankie Lindsey told ABC News the gunman, Michael McLendon, used a machine gun to murder 10 men, women, and children, including his mother and grandparents, before killing himself:

He opened up on us with an AK-47. That's what it looked like. It could have been an M-16, but it was an assault rifle, automatic. And he burst about 15 to 18 rounds on our vehicle, all at once.

Assuming that's accurate, McLendon's weapon probably was already illegal, since federal law prohibits civilian possession of post-1986 machine guns and requires an arduous and expensive licensing process for machine guns made before then. And if McLendon did use a fully automatic gun, a ban on "assault weapons" could not possibly have made a difference, since the firearms covered by such laws are all semiautomatic, firing once per trigger pull. If Lindsey was mistaken, and McLendon's gun was in fact one of the semiautomatic models covered by the now-expired federal "assault weapon" ban, it's doubtful that he would have done less damage with a gun that did not have a sufficiently "military-style" appearance to qualify for the ban. Even a ban on magazines that hold more than 10 rounds (another provision of the "assault weapon" law), assuming it prevented McLendon from obtaining such magazines, would not necessarily have reduced the death toll, since magazines can be switched in seconds and McLendon was, in any event, carrying other weapons.

It's instructive to compare McLendon's rampage to today's shooting spree in Germany. A teenager killed 15 people (five more than McLendon) at a technical school in Winnenden and outside a supermarket in Wendlingen. It's not clear exactly what type of gun he used. But according to Reuters, "German television reported that he may have used a legally registered gun that [was] kept in his family's home." As The Washington Post notes, "Firearms are tightly regulated in Germany, but the country has been afflicted by other mass, lone-gunman shootings in the past several years." The reasons for those attacks defy easy explanation, just as McLendon's neighbors were at a loss to understand why he did what he did. Reuters nevertheless instantly located the root of such violence in our Bill of Rights:

Mass shootings have become a feature of life in the United States....Guns are widely available for purchase in the United States, a country that prides itself on the right to own weapons for self defense and hunting.

Last month I noted Attorney General Eric Holder's reiteration of President Obama's support for reviving the "assault weapon" ban.