It seems a lot of gun shootings are done in a rage by people who have hidden, or maybe not so hidden, mental health/anger management issues that suddenly pop up when something that really makes them mad occurs.
Besides the Virginia rampage, I seem to be hearing more about fathers killing their kids in a rage after a separation. That happened in Maryland recently where the father essentially lynched and hung two toddlers in trees outside. It also occurred to my sister's friend's family in Texas, where the estranged father killed one daughter and shot another who survived before killing himself.
Mental health screenings, where the counselor asks things like why they want a gun and if they have ever dealt with anger management issues before, might not stop all of these shootings. But maybe that might deter some and get the would-be gun owners to think more before they buy a gun. And that's a good thing in itself - to get even seemingly sane gun owners to examine their need for guns.
I know you get into issues like who gives these screenings and would gun owners have to carry a card affirming they've had their heads examined, and I say all that can be worked out.
And maybe we should look at what countries like Germany and Canada are doing to control homicide. Government statistics show that the U.S. leads almost all major industrialized countries in murder rates. In 2004, there were 5.5 homicides for every 100,000 persons in the U.S., compared to 1.9 in Canada and 1.1 in Germany. Most industrialized countries had homicide rates below the 2.5 mark. The only one that was above the U.S. was Russia at about 20.